Arc path forming unit and direct current relay comprising same

ABSTRACT

An arc path forming unit and a direct current relay are disclosed. An arc path forming unit according to an embodiment of the present invention comprises: a magnet frame extending in a longitudinal direction; and a plurality of main magnet units disposed in the width direction of the magnet frame. The surfaces, which face each other, of the main magnet units have the same polarity. Therefore, magnetic fields that repel each other are generated in a space between the respective main magnet units. An electromagnetic force in the direction oriented toward the outside of the arc path forming unit is formed by means of the magnetic fields. Thus, a generated arc can move in the direction of the electromagnetic force so as to be stably extinguished. As a result, various members positioned in the center of the direct current relay are prevented from being damaged by the arc.

TECHNICAL FIELD

The present disclosure relates to an arc path forming unit and a directcurrent (DC) relay comprising the same, and more particularly, to an arcpath forming unit having a structure capable of forming an arc dischargepath using electromagnetic force and preventing damage on a DC relay,and a DC relay comprising the same.

BACKGROUND ART

A direct current (DC) relay is a device that transmits a mechanicaldriving signal or a current signal using the principle of anelectromagnet. The DC relay is also called a magnetic switch andgenerally classified as an electrical circuit switching device.

A DC relay includes a fixed contact and a movable contact. The fixedcontact is electrically connected to an external power supply and aload. The fixed contact and the movable contact may be brought intocontact with or spaced apart from each other.

By the contact and separation between the fixed contact and the movablecontact, electrical connection or disconnection through the DC relay isachieved. Such movement like the contact or separation is made by adrive unit that applies driving force.

When the fixed contact and the movable contact are separated from eachother, an arc is generated between the fixed contact and the movablecontact. The arc is a flow of high-pressure and high-temperaturecurrent. Accordingly, the generated arc must be rapidly discharged fromthe DC relay through a preset path.

An arc discharge path is formed by magnets provided in the DC relay. Themagnets produce magnetic fields in a space where the fixed contact andthe movable contact are in contact with each other. The arc dischargepath may be formed by the formed magnetic fields and electromagneticforce generated by a flow of current.

Referring to FIG. 1, a space in which fixed contacts 1100 and movablecontacts 1200 provided in a DC relay 1000 according to the prior art arein contact with each other is shown. As described above, permanentmagnets 1300 are provided in the space.

The permanent magnets 1300 include a first permanent magnet 1310disposed at an upper side and a second permanent magnet 1320 disposed ata lower side. A lower side of the first permanent magnet 1310 ismagnetized to an N pole, and an upper side of the second permanentmagnet 1320 is magnetized to an S pole. Accordingly, a magnetic field isgenerated in a direction from the upper side to the lower side.

(a) of FIG. 1 illustrates a state in which current flows in through theleft fixed contact 1100 and flows out through the right fixed contact1100. According to the Fleming's left-hand rule, electromagnetic forceis formed outward as indicated with a hatched arrow. Accordingly, agenerated arc can be discharged to outside along the direction of theelectromagnetic force.

On the other hand, (b) of FIG. 1 illustrates a state in which currentflows in through the right fixed contact 1100 and flows out through theleft fixed contact 1100. According to the Fleming's left-hand rule,electromagnetic force is formed inward as indicated with a hatchedarrow. Accordingly, a generated arc moves inward along the direction ofthe electromagnetic force.

Several members for driving the movable contact 1200 to be moved up anddown (in a vertical direction) are provided in a central portion of theDC relay 1000, that is, in a space between the fixed contacts 1100. Forexample, a shaft, a spring member inserted through the shaft, etc. areprovided at the position.

Therefore, when an arc generated as illustrated in (b) of FIG. 1 ismoved toward the central portion, there is a risk that various membersprovided at the position may be damaged by energy of the arc.

In addition, as illustrated in FIG. 1, a direction of electromagneticforce formed inside the related art DC relay 1000 depends on a directionof current flowing through the fixed contacts 1200. Therefore, currentpreferably flows only in a preset direction, namely, in a directionillustrated in (a) of FIG. 1.

In other words, a user must consider the direction of the currentwhenever using the DC relay. This may cause inconvenience to the use ofthe DC relay. In addition, regardless of the user's intention, asituation in which a flowing direction of current applied to the DCrelay is changed due to an inexperienced operation or the like cannot beexcluded.

In this case, the members disposed in the central portion of the DCrelay may be damaged by the generated arc. This may be likely to reducethe lifespan of the DC relay and cause a safety accident.

Korean Registration Application No. 10-1696952 discloses a DC relay.Specifically, a DC relay having a structure capable of preventingmovement of a movable contact using a plurality of permanent magnets isdisclosed.

The DC relay having the structure can prevent the movement of themovable contact by using the plurality of permanent magnets, but thereis a limitation in that any method for controlling a direction of an arcdischarge path is not considered.

Korean Registration Application No. 10-1216824 discloses a DC relay.Specifically, a DC relay having a structure capable of preventingarbitrary separation between a movable contact and a fixed contact usinga damping magnet is disclosed.

However, the DC relay having the structure merely proposes a method formaintaining a contact state between the movable contact and the fixedcontact. That is, there is a limitation in that a method for forming adischarge path for an arc generated when the movable contact and thefixed contact are separated from each other is not introduced.

-   Korean Registration Application No. 10-1696952 (Jan. 16, 2017)-   Korean Registration Application No. 10-1216824 (Dec. 28, 2012)

DISCLOSURE OF INVENTION Technical Problem

The present disclosure describes an arc path forming unit having astructure capable of solving those problems, and a DC relay having thesame.

The present disclosure also describes an arc path forming unit having astructure in which a generated arc does not extend toward a centralportion, and a DC relay having the same.

The present disclosure further describes an arc path forming unit havinga structure capable of forming an arc discharge path toward an outside,regardless of a direction of current applied to a fixed contact, and aDC relay having the same.

The present disclosure further describes an arc path forming unit havinga structure capable of minimizing damage on members located at a centralportion due to a generated arc, and a DC relay having the same.

The present disclosure further describes an arc path forming unit havinga structure capable of sufficiently extinguishing a generated arc whilethe generated arc moves, and a DC relay having the same.

The present disclosure further describes an arc path forming unit havinga structure capable of increasing strength of magnetic fields forforming an arc discharge path, and a DC relay having the same.

The present disclosure further describes an arc path forming unit havinga structure capable of effectively discharging a generated arc, and a DCrelay having the same.

The present disclosure further describes an arc path forming unit havinga structure capable of changing an arc discharge path without anexcessive structural change, and a DC relay having the same.

Technical Solution

To achieve those aspects of the subject matter described in thisapplication, an arc path forming unit may include a magnet frame havingan inner space, and comprising two pairs of surfaces facing each otherand surrounding the inner space, and main magnets coupled to any onepair of surfaces extending shorter among the two pairs of surfaces. Afixed contactor and a movable contactor configured to be brought intocontact with or separated from the fixed contactor may be accommodatedin the inner space. The main magnets coupled to the one pair of surfacesmay have facing surfaces, respectively, that face each other, and have asame polarity so as to form a discharge path of an arc generated whenthe fixed contactor and the movable contactor are separated from eachother.

The main magnets of the arc path forming unit may include a first mainmagnet coupled to any one of the one pair of surfaces, and a second mainmagnet coupled to another one of the one pair of surfaces and disposedto face the first main magnet.

In the arc path forming unit, facing surfaces of the third main magnetand the second main magnet that face each other may have a samepolarity.

In the arc path forming unit, the facing surfaces of the first mainmagnet and the second main magnet that face each other may have an Npole.

The arc path forming unit may include sub magnets coupled to anotherpair of surfaces extending longer among the two pairs of surfaces of themagnet frame, and facing surfaces of the sub magnets that face eachother may have a same polarity.

In the arc path forming unit, the facing surfaces of the sub magnetsthat face each other may have a different polarity from the polarity ofthe facing surfaces of the first main magnet and the second main magnet.

In the arc path forming unit, arc discharge openings may be formedthrough another pair of surfaces extending shorter among the two pairsof surfaces of the magnet frame such that the inner space communicateswith an outside of the magnet frame.

In the arc path forming unit, the first main magnet may be provided inplurality, and the plurality of first main magnets may be spaced apartfrom each other by a predetermined distance. The second main magnet maybe provided in plurality, and the plurality of second main magnets maybe spaced apart from each other by a predetermined distance.

In the arc path forming unit, magnetization members may be disposedbetween the plurality of first main magnets and between the plurality ofsecond main magnets, respectively, such that the plurality of first mainmagnets and the magnetization member are connected to each other and theplurality of second main magnets and the magnetization member areconnected to each other.

To achieve those aspects of the subject matter described in thisapplication, a Direct current (DC) relay may include a fixed contactor,a movable contactor configured to be brought into contact with orseparated from the fixed contactor, an arc path forming unit having aninner space for accommodating the fixed contactor and the movablecontactor, and configured to produce magnetic fields in the inner spaceso as to form a discharge path of an arc that is generated when thefixed contactor and the movable contactor are separated from each other,and a frame part configured to accommodate the arc path forming unit.The arc path forming unit may include a magnet frame having an innerspace, and comprising two pairs of surfaces facing each other andsurrounding the inner space, and main magnets accommodated in the innerspace and coupled to any one pair of surfaces extending shorter amongthe two pairs of surfaces. A fixed contactor and a movable contactorconfigured to be brought into contact with or separated from the fixedcontactor may be accommodated in the inner space. The main magnetscoupled to the one pair of surfaces may have facing surfaces,respectively, which face each other and have a same polarity so as toform a discharge path of an arc generated when the fixed contactor andthe movable contactor are separated from each other.

In the DC relay, the main magnets may include a first main magnetcoupled to any one of the one pair of surfaces, and a second main magnetcoupled to another one of the one pair of surfaces and disposed to facethe first main magnet. Facing surfaces of the first main magnet and thesecond main magnet that face each other may have a same polarity.

In the DC relay, the arc path forming unit may include sub magnetscoupled to another pair of surfaces extending longer among the two pairsof surfaces of the frame part. Facing surfaces of the sub magnets thatface each other may have a same polarity. The facing surfaces of the submagnets that face each other may have a different polarity from thepolarity of the facing surfaces of the first main magnet and the secondmain magnet.

In the DC relay, the first main magnet may be provided in plurality, andthe plurality of first main magnets may be spaced apart from each otherby a predetermined distance. The second main magnet may be provided inplurality, and the plurality of second main magnets may be spaced apartfrom each other by a predetermined distance.

In the DC relay, one of the plurality of first main magnets may beshorter than another first main magnet, and one of the plurality ofsecond main magnets may be shorter than another second main magnet.

In the DC relay, magnetization members may be disposed between theplurality of first main magnets and between the plurality of second mainmagnets, respectively, such that the plurality of first main magnets andthe magnetization member are connected to each other and the pluralityof second main magnets and the magnetization member are connected toeach other.

In the DC relay, the first main magnet and the second main magnet mayinclude opposing surfaces opposite to the facing surfaces, respectively,and coming in contact with the surfaces of the magnet frame. A mainmagnetic field may be produced between the first main magnet and thesecond main magnet and a sub magnetic field may be produced between thefacing surfaces and the opposing surfaces of the first main magnet andthe second main magnet, such that the sub magnetic field strengthens themain magnetic field.

Advantageous Effects of Invention

According to the present disclosure, the following effects can beachieved.

First, main magnets provided at a magnet frame may be arranged to faceeach other. Sides of the main magnets that face each other may have thesame polarity. Accordingly, in a space between the main magnets,magnetic fields may be produced in a direction of repelling orattracting each other.

This can change proceeding directions of the magnetic fields, such thatelectromagnetic force generated in the vicinity of each fixed contactcan be generated in a direction away from a center of the magnet frame.This can result in forming a path (A.P) of a generated arc in adirection away from the center of the magnet frame as well.

The sides of the main magnets that face each other may have the samepolarity. Accordingly, in a space between the main magnets, magneticfields may be produced in a direction of repelling or attracting eachother.

As a result, the magnetic field produced near each fixed contact canflow in a direction away from the center of the magnet frame, regardlessof a direction of current applied to each fixed contact. The generatedarc can also move away from the center of the magnet frame, regardlessof the direction of the current applied to each fixed contact.

This can prevent the generated arc from moving toward the center of themagnet frame. Thus, each member disposed at a central portion of a DCrelay can be prevented from being damaged due to the arc.

In addition, the generated arc can extend toward an outside of the fixedcontacts, which is a wider space, other than toward the center of themagnet frame, which is a narrow space, i.e., toward a space between thefixed contacts. Accordingly, the arc can be sufficiently extinguishedwhile moving toward the wider space.

Main magnetic fields can be produced among a plurality of main magnetsin the magnet frame. Sub magnetic fields can also be produced by themain magnets themselves. The sub magnetic fields can strengthen the mainmagnetic fields.

Accordingly, the main magnetic fields produced by the plurality of mainmagnets can be strengthened. This can also increase strength ofelectromagnetic force generated by the main magnetic fields, so that anarc discharge path can be formed effectively.

The magnet frame may also include sub magnets in addition to the mainmagnets. The sub magnets may be disposed on surfaces of the magnet framewhere the main magnets are not located. The sub magnets may produce submagnetic fields to strengthen the main magnetic fields produced by themain magnets.

Accordingly, the main magnetic fields produced by the main magnets canbe strengthened. This can also increase strength of electromagneticforce generated, so that an arc discharge path can be formedeffectively.

In addition, the main magnets disposed at the magnet frame can beconnected to each other by a magnetization member. Accordingly, themagnetization member may have the same polarity as the main magnets.

Therefore, the magnetic fields can be produced not only by the mainmagnets but also by the magnetization members. The magnetic fields maybe produced in the same direction and thus can be strengthened.

Arc discharge openings may be formed at the magnet frame. The arcdischarge openings may be formed through the magnet frame, such that anarc can be discharged through a formed path. The arc discharge openingsmay be located on extension lines of magnetic fields produced by themain magnets or by the main magnets and the sub magnets.

Accordingly, when a generated arc is moved along the formed dischargepath, the arc may move toward the arc discharge openings. The generatedarc can thusly be effectively discharged from the magnet frame.

In one implementation, each main magnet may have a different length.That is, the main magnets located on respective sides of the magnetframe may have different lengths.

Accordingly, a direction of a magnetic field produced by each mainmagnet can change only by changing the length of the main magnet.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a planar view illustrating paths on which an arc is generatedin a DC relay according to the related art.

FIG. 2 is a perspective view of a DC relay in accordance with animplementation.

FIG. 3 is a cross-sectional view of the DC relay of FIG. 2.

FIG. 4 is an exploded perspective view illustrating a magnet assemblydisposed in the DC relay of FIG. 2.

FIG. 5 is a perspective view illustrating a magnet assembly inaccordance with one implementation.

FIG. 6 is a planar view of the magnet assembly of FIG. 5.

FIG. 7 is a planar view illustrating a magnet assembly in accordancewith a modified example of the implementation of FIG. 5.

FIG. 8 is a planar view illustrating a magnet assembly in accordancewith a modified example of the implementation of FIG. 5.

FIG. 9 is a planar view illustrating a magnet assembly in accordancewith a modified example of the implementation of FIG. 5.

FIG. 10 is a perspective view illustrating a magnet assembly inaccordance with another implementation.

FIG. 11 is a planar view of the magnet assembly of FIG. 10.

FIG. 12 is a planar view illustrating a magnet assembly in accordancewith a modified example of the implementation of FIG. 10.

FIG. 13 is a planar view illustrating a magnet assembly in accordancewith a modified example of the implementation of FIG. 10.

FIG. 14 is a planar view illustrating a magnet assembly in accordancewith a modified example of the implementation of FIG. 10.

FIG. 15 is a planar view illustrating a moving (proceeding, flowing)direction of an arc generated inside the magnet assembly of FIGS. 5 and6.

FIG. 16 is a planar view illustrating a moving direction of an arcgenerated inside the magnet assembly of FIG. 7.

FIG. 17 is a planar view illustrating a moving direction of an arcgenerated inside the magnet assembly of FIG. 8.

FIG. 18 is a planar view illustrating a moving direction of an arcgenerated inside the magnet assembly of FIG. 9.

FIG. 19 is a planar view illustrating a moving direction of an arcgenerated inside the magnet assembly of FIGS. 10 and 11.

FIG. 20 is a planar view illustrating a moving direction of an arcgenerated inside the magnet assembly of FIG. 12.

FIG. 21 is a planar view illustrating a moving direction of an arcgenerated inside the magnet assembly of FIG. 13.

FIG. 22 is a planar view illustrating a moving direction of an arcgenerated inside the magnet assembly of FIG. 14.

MODE FOR THE INVENTION

Hereinafter, an arc path forming unit and a DC relay according toimplementations of the present disclosure will be described in detailwith reference to the accompanying drawings.

In the following description, descriptions of some components may beomitted to help understanding of the present disclosure.

1. Definition of Terms

It will be understood that when an element is referred to as being“connected with” another element, the element can be connected with theanother element or intervening elements may also be present.

In contrast, when an element is referred to as being “directly connectedwith” another element, there are no intervening elements present.

A singular representation used herein may include a pluralrepresentation unless it represents a definitely different meaning fromthe context.

The term “magnetize” used in the following description refers to aphenomenon in which an object exhibits magnetism in a magnetic field.

The term “polarities” used in the following description refers todifferent properties belonging to an anode and a cathode of anelectrode. In one implementation, the polarities may be classified intoan N pole or an S pole.

The term “electric connection” used in the following description means astate in which two or more members are electrically connected.

The term “arc path” used in the following description means a paththrough which a generated arc is moved or extinguished.

The terms “left”, “right”, “top”, “bottom”, “front” and “rear” used inthe following description will be understood based on a coordinatesystem illustrated in FIG. 2.

2. Description of Configuration of DC Relay 10 According toImplementation

Referring to FIGS. 2 and 3, a DC relay 10 according to an implementationmay include a frame part 100, an opening/closing part 200, a core part300, and a movable contactor part 400.

Referring to FIGS. 4 to 14, the DC relay 10 may include an arc pathforming unit 500, 600. The arc path forming unit 500, 600 may form(define) a discharge path of a generated arc.

Hereinafter, each configuration of the DC relay 10 according to theimplementation will be described with reference to the accompanyingdrawings, and the arc path forming unit 500, 600 will be described as aseparate clause.

(1) Description of Frame Part 100

The frame part 100 may define appearance of the DC relay 10. Apredetermined space may be defined inside the frame part 100. Variousdevices for the DC relay 10 to perform functions for applying or cuttingoff current transmitted from outside may be accommodated in the space.

That is, the frame part 100 may function as a kind of housing.

The frame part 100 may be formed of an insulating material such assynthetic resin. This may prevent an arbitrary electrical connectionbetween inside and outside of the frame part 100.

The frame part 100 may include an upper frame 110, a lower frame 120, aninsulating plate 130, and a supporting plate 140.

The upper frame 110 may define an upper side of the frame part 100. Apredetermined space may be defined inside the upper frame 110.

The opening/closing part 200 and the movable contactor part 400 may beaccommodated in an inner space of the upper frame 110. The arc pathforming unit 500, 600 may also be accommodated in the inner space of theupper frame 110.

The upper frame 110 may be coupled to the lower frame 120. Theinsulating plate 130 and the supporting plate 140 may be disposed in aspace between the upper frame 110 and the lower frame 120.

A fixed contactor 220 of the opening/closing part 200 may be located onone side of the upper frame 110, for example, on an upper side of theupper frame 110 in the illustrated implementation. The fixed contactor220 may be partially exposed to the upper side of the upper frame 110,to be electrically connected to an external power supply or a load.

To this end, a through hole through which the fixed contactor 220 iscoupled may be formed at the upper side of the upper frame 110.

The lower frame 120 may define a lower side of the frame part 100. Apredetermined space may be defined inside the lower frame 120. The corepart 300 may be accommodated in the inner space of the lower frame 120.

The lower frame 120 may be coupled to the upper frame 110. Theinsulating plate 130 and the supporting plate 140 may be disposed in aspace between the lower frame 120 and the upper frame 110.

The insulating plate 130 and the supporting plate 140 may electricallyand physically isolate the inner space of the upper frame 110 and theinner space of the lower frame 120 from each other.

The insulating plate 130 may be located between the upper frame 110 andthe lower frame 120. The insulating plate 130 may allow the upper frame110 and the lower frame 120 to be electrically spaced apart from eachother. To this end, the frame part 130 may be formed of an insulatingmaterial such as synthetic resin.

The insulating plate 130 can prevent arbitrary electrical connectionbetween the opening/closing part 200, the movable contactor part 400,and the arc path forming unit 500, 600 that are accommodated in theupper frame 110 and the core part 300 accommodated in the lower frame120.

A through hole (not illustrated) may be formed through a central portionof the insulating plate 130. A shaft 440 of the movable contactor part400 may be coupled through the through hole (not illustrated) to bemovable up and down.

The insulating plate 140 may be located on a lower side of theinsulating plate 130. The insulating plate 130 may be supported by thesupporting plate 140.

The supporting plate 140 may be located between the upper frame 110 andthe lower frame 120.

The supporting plate 140 may allow the upper frame 110 and the lowerframe 120 to be electrically spaced apart from each other. In addition,the supporting plate 140 may support the insulating plate 130.

For example, the supporting plate 140 may be formed of a magneticmaterial. In addition, the supporting plate 140 may configure a magneticcircuit together with a yoke 330 of the core part 300. The magneticcircuit may apply driving force to a movable core 320 of the core part300 so as to move toward a fixed core 310.

A through hole (not illustrated) may be formed through a central portionof the supporting plate 140. The shaft 440 may be coupled through thethrough hole (not illustrated) to be movable up and down.

Therefore, when the movable core 320 is moved toward or away from thefixed core 310, the shaft 440 and the movable contactor 430 connected tothe shaft 440 may also be moved in the same direction.

(2) Description of Opening/Closing Part 200

The opening/closing unit 200 may allow current to be applied to or cutoff from the DC relay 10 according to an operation of the core part 300.Specifically, the opening/closing part 200 may allow or block anapplication of current as the fixed contactor 220 and the movablecontactor 430 are brought into contact with or separated from eachother.

The opening/closing part 200 may be accommodated in the inner space ofthe upper frame 110. The opening/closing part 200 may be electricallyand physically spaced apart from the core part 300 by the insulatingplate 130 and the supporting plate 140.

The opening/closing part 200 may include an arc chamber 210, a fixedcontactor 220, and a sealing member 230.

In addition, the arc path forming unit 500, 600 may be disposed outsidethe arc chamber 210. The arc path forming unit 500, 600 may form amagnetic field for forming an arc path A.P of an arc generated insidethe arc chamber 210. A detailed description thereof will be given later.

The arc chamber 210 may be configured to extinguish an arc at its innerspace, when the arc is generated as the fixed contactor 220 and themovable contactor 430 are separated from each other. Therefore, the arcchamber 210 may also be referred to as an “arc extinguishing portion”.

The arc chamber 210 may hermetically accommodate the fixed contactor 220and the movable contactor 430. That is, the fixed contactor 220 and themovable contactor 430 may be accommodated in the arc chamber 210.Accordingly, the arc generated when the fixed contactor 220 and themovable contactor 430 are separated from each other may not arbitrarilyleak to the outside of the arc chamber 210.

The arc chamber 210 may be filled with extinguishing gas. Theextinguishing gas may extinguish the generated arc and may be dischargedto the outside of the DC relay 10 through a preset path. To this end, acommunication hole (not illustrated) may be formed through a wallsurrounding the inner space of the arc chamber 210.

The arc chamber 210 may be formed of an insulating material. Inaddition, the arc chamber 210 may be formed of a material having highpressure resistance and high heat resistance. This is because thegenerated arc is a flow of electrons of high-temperature andhigh-pressure. In one implementation, the arc chamber 210 may be formedof a ceramic material.

A plurality of through holes may be formed through an upper side of thearc chamber 210. The fixed contactor 220 may be coupled through each ofthe through holes (not illustrated).

In the illustrated implementation, the fixed contactor 220 may beprovided by two, namely, a first fixed contactor 220 a and a secondfixed contactor 220 b. Accordingly, the through hole (not illustrated)formed through the upper side of the arc chamber 210 may also beprovided by two.

When the fixed contactors 220 are inserted through the through holes,the through holes may be sealed. That is, the fixed contactor 220 may behermetically coupled to the through hole. Accordingly, the generated arccannot be discharged to the outside through the through hole.

A lower side of the arc chamber 210 may be open. That is, the lower sideof the arc chamber 210 may be in contact with the insulating plate 130and the sealing member 230. That is, the lower side of the arc chamber210 may be sealed by the insulating plate 130 and the sealing member230.

Accordingly, the arc chamber 210 can be electrically and physicallyisolated from an outer space of the upper frame 110.

The arc extinguished in the arc chamber 210 may be discharged to theoutside of the DC relay 10 through a preset path. In one implementation,the extinguished arc may be discharged to the outside of the arc chamber210 through the communication hole (not illustrated).

The fixed contactor 220 may be brought into contact with or separatedfrom the movable contactor 430, so as to electrically connect ordisconnect the inside and the outside of the DC relay 10.

Specifically, when the fixed contactor 220 is brought into contact withthe movable contactor 430, the inside and the outside of the DC relay 10may be electrically connected. On the other hand, when the fixedcontactor 220 is separated from the movable contactor 430, theelectrical connection between the inside and the outside of the DC relay10 may be released.

As the name implies, the fixed contactor 220 does not move. That is, thefixed contactor 220 may be fixedly coupled to the upper frame 110 andthe arc chamber 210. Accordingly, the contact and separation between thefixed contactor 220 and the movable contactor 430 can be implemented bythe movement of the movable contactor 430.

One end portion of the fixed contactor 220, for example, an upper endportion in the illustrated implementation, may be exposed to the outsideof the upper frame 110. A power supply or a load may be electricallyconnected to the one end portion.

The fixed contactor 220 may be provided in plurality. In the illustratedimplementation, the fixed contactor 220 may be provided by two,including a first fixed contactor 220 a on a left side and a secondfixed contactor 220 b on a right side.

The first fixed contactor 220 a may be located to be biased to one sidefrom a center of the movable contactor 430 in a longitudinal direction,namely, to the left in the illustrated implementation. Also, the secondfixed contactor 220 b may be located to be biased to another side fromthe center of the movable contactor 430 in the longitudinal direction,namely, to the right in the illustrated implementation.

A power supply may be electrically connected to any one of the firstfixed contactor 220 a and the second fixed contactor 220 b. Also, a loadmay be electrically connected to another one of the first fixedcontactor 220 a and the second fixed contactor 220 b.

The DC relay 10 may form an arc path A.P regardless of a direction ofthe power supply or load connected to the fixed contactor 220. This canbe achieved by the arc path forming unit 500, 600, and a detaileddescription thereof will be described later.

Another end portion of the fixed contactor 220, for example, a lower endportion in the illustrated implementation may extend toward the movablecontactor 430.

When the movable contactor 430 is moved toward the fixed contactor 220,namely, upward in the illustrated implementation, the lower end portionof the fixed contactor 220 may be brought into contact with the movablecontactor 430. Accordingly, the outside and the inside of the DC relay10 can be electrically connected.

The lower end portion of the fixed contactor 220 may be located insidethe arc chamber 210.

When control power is cut off, the movable contactor 430 may beseparated from the fixed contactor 220 by elastic force of a returnspring 360.

At this time, as the fixed contactor 220 and the movable contactor 430are separated from each other, an arc may be generated between the fixedcontactor 220 and the movable contactor 430. The generated arc may beextinguished by the extinguishing gas inside the arc chamber 210, andmay be discharged to the outside along a path formed by the arc pathforming unit 500, 600.

The sealing member 230 may block arbitrary communication between the arcchamber 210 and the inner space of the upper frame 110. The sealingmember 230 may seal the lower side of the arc chamber 210 together withthe insulating plate 130 and the supporting plate 140.

In detail, an upper side of the sealing member 230 may be coupled to thelower side of the arc chamber 210. A radially inner side of the sealingmember 230 may be coupled to an outer circumference of the insulatingplate 130, and a lower side of the sealing member 230 may be coupled tothe supporting plate 140.

Accordingly, the arc generated in the arc chamber 210 and the arcextinguished by the extinguishing gas may not arbitrarily flow into theinner space of the upper frame 110.

In addition, the sealing member 230 may prevent an inner space of acylinder 370 from arbitrarily communicating with the inner space of theframe part 100.

(3) Description of Core Part 300

The core part 300 may allow the movable contactor part 400 to moveupward as control power is applied. In addition, when the control poweris not applied any more, the core part 300 may allow the movablecontactor part 400 to move downward again.

As described above, the core part 300 may be electrically connected toan external power supply (not illustrated) to receive control power.

The core part 300 may be located below the opening/closing part 200. Thecore part 300 may be accommodated in the lower frame 120. The core part300 and the opening/closing part 200 may be electrically and physicallyspaced apart from each other by the insulating plate 130 and thesupporting plate 140.

The movable contactor part 400 may be located between the core part 300and the opening/closing part 200. The movable contactor part 400 may bemoved by driving force applied by the core part 300. Accordingly, themovable contactor 430 and the fixed contactor 220 can be brought intocontact with each other so that the DC relay 10 can be electricallyconnected.

The core part 300 may include a fixed core 310, a movable core 320, ayoke 330, a bobbin 340, coils 350, a return spring 360, and a cylinder370.

The fixed core 310 may be magnetized by a magnetic field generated inthe coils 350 so as to generate electromagnetic attractive force. Themovable core 320 may be moved toward the fixed core 310 (upward in FIG.3) by the electromagnetic attractive force.

The fixed core 310 may not move. That is, the fixed core 310 may befixedly coupled to the supporting plate 140 and the cylinder 370.

The movable core 310 may have any shape capable of being magnetized bythe magnetic field so as to generate electromagnetic force. In oneimplementation, the fixed core 310 may be implemented as a permanentmagnet or an electromagnet.

The fixed core 310 may be partially accommodated in an upper spaceinside the cylinder 370. Further, an outer circumference of the fixedcore 310 may come in contact with an inner circumference of the cylinder370.

The fixed core 310 may be located between the supporting plate 140 andthe movable core 320.

A through hole (not illustrated) may be formed through a central portionof the fixed core 310. The shaft 440 may be coupled through the throughhole (not illustrated) to be movable up and down.

The fixed core 310 may be spaced apart from the movable core 320 by apredetermined distance. Accordingly, a distance by which the movablecore 320 can move toward the fixed core 310 may be limited to thepredetermined distance. Accordingly, the predetermined distance may bedefined as a “moving distance of the movable core 320”.

One end portion of the return spring 360, namely, an upper end portionin the illustrated implementation may be brought into contact with thelower side of the fixed core 310. When the movable core 320 is movedupward as the fixed core 310 is magnetized, the return spring 360 may becompressed and store restoring force.

Accordingly, when application of control power is released and themagnetization of the fixed core 310 is terminated, the movable core 320may be returned to the lower side by the restoring force.

When control power is applied, the movable core 320 may be moved towardthe fixed core 310 by the electromagnetic attractive force generated bythe fixed core 310.

As the movable core 320 is moved, the shaft 440 coupled to the movablecore 320 may be moved toward the fixed core 310, namely, upward in theillustrated implementation. In addition, as the shaft 440 is moved, themovable contactor part 400 coupled to the shaft 440 may be moved upward.

Accordingly, the fixed contactor 220 and the movable contactor 430 maybe brought into contact with each other so that the DC relay 10 can beelectrically connected to the external power supply and the load.

The movable core 320 may have any shape capable of receiving attractiveforce by electromagnetic force. In one implementation, the movable core320 may be formed of a magnetic material or implemented as a permanentmagnet or an electromagnet.

The movable core 320 may be accommodated inside the cylinder 370. Also,the movable core 320 may be moved inside the cylinder 370 in thelongitudinal direction of the cylinder 370, for example, in the verticaldirection in the illustrated implementation.

Specifically, the movable core 320 may move toward the fixed core 310and away from the fixed core 310.

The movable core 320 may be coupled to the shaft 440. The movable core320 may move integrally with the shaft 440. When the movable core 320moves upward or downward, the shaft 440 may also move upward ordownward. Accordingly, the movable contactor 430 may also move upward ordownward.

The movable core 320 may be located below the fixed core 310. Themovable core 320 may be spaced apart from the fixed core 310 by apredetermined distance. As described above, the predetermined distancemay be defined as the moving distance of the movable core 320 in thevertical (up/down) direction.

The movable core 320 may extend in the longitudinal direction. A hollowportion extending in the longitudinal direction may be recessed into themovable core 320 by a predetermined distance. The return spring 360 andthe shaft 440 coupled through the return spring 360 may be partiallyaccommodated in the hollow portion.

A through hole may be formed through a lower side of the hollow portionin the longitudinal direction. The hollow portion and the through holemay communicate with each other. A lower end portion of the shaft 440inserted into the hollow portion may proceed (be inserted) toward thethrough hole.

A space portion may be recessed into a lower end portion of the movablecore 320 by a predetermined distance. The space portion may communicatewith the through hole. A lower head portion of the shaft 440 may belocated in the space portion.

The yoke 330 may configure a magnetic circuit as control power isapplied. The magnetic circuit formed by the yoke 330 may control adirection of electromagnetic field generated by the coils 350.

Accordingly, when control power is applied, the coils 350 may generate amagnetic field in a direction in which the movable core 320 moves towardthe fixed core 310. The yoke 330 may be formed of a conductive materialcapable of allowing electrical connection.

The yoke 330 may be accommodated inside the lower frame 120. The yoke330 may surround the coils 350. The coils 350 may be accommodated in theyoke 330 with being spaced apart from an inner circumferential surfaceof the yoke 330 by a predetermined distance.

The bobbin 340 may be accommodated inside the yoke 330. That is, theyoke 330, the coils 350, and the bobbin 340 on which the coils 350 arewound may be sequentially disposed in a direction from an outercircumference of the lower frame 120 to a radially inner side.

An upper side of the yoke 330 may come in contact with the supportingplate 140. In addition, the outer circumference of the yoke 330 may comein contact with an inner circumference of the lower frame 120 or may belocated to be spaced apart from the inner circumference of the lowerframe 120 by a predetermined distance.

The coils 350 may be wound around the bobbin 340. The bobbin 340 may beaccommodated inside the yoke 330.

The bobbin 340 may include upper and lower portions formed in a flatshape, and a cylindrical pole portion extending in the longitudinaldirection to connect the upper and lower portions. That is, the bobbin340 may have a bobbin shape.

The upper portion of the bobbin 340 may come in contact with the lowerside of the supporting plate 140. The coils 350 may be wound around thepole portion of the bobbin 340. A wound thickness of the coils 350 maybe equal to or smaller than a diameter of the upper and lower portionsof the bobbin 340.

A hollow portion may be formed through the pole portion of the bobbin340 extending in the longitudinal direction. The cylinder 370 may beaccommodated in the hollow portion. The pole portion of the bobbin 340may be disposed to have the same central axis as the fixed core 310, themovable core 320, and the shaft 440.

The coils 350 may generate a magnetic field as control power is applied.The fixed core 310 may be magnetized by the electric field generated bythe coils 350 and thus an electromagnetic attractive force may beapplied to the movable core 320.

The coils 350 may be wound around the bobbin 340. Specifically, thecoils 350 may be wound around the pole portion of the bobbin 340 andstacked on a radial outside of the pole portion. The coils 350 may beaccommodated inside the yoke 330.

When control power is applied, the coils 350 may generate a magneticfield. In this case, strength or direction of the magnetic fieldgenerated by the coils 350 may be controlled by the yoke 330. The fixedcore 310 may be magnetized by the electric field generated by the coils350.

When the fixed core 310 is magnetized, the movable core 320 may receiveelectromagnetic force, namely, attractive force in a direction towardthe fixed core 310. Accordingly, the movable core 320 can be movedtoward the fixed core 310, namely, upward in the illustratedimplementation.

The return spring 360 may apply restoring force to return the movablecore 320 to its original position when control power is not applied anymore after the movable core 320 is moved toward the fixed core 310.

The return spring 360 may store restoring force while being compressedas the movable core 320 is moved toward the fixed core 310. At thistime, the stored restoring force may preferably be smaller than theelectromagnetic attractive force, which is exerted on the movable core320 as the fixed core 310 is magnetized. This can prevent the movablecore 320 from being returned to its original position by the returnspring 360 while control power is applied.

When control power is not applied any more, only the restoring force bythe return spring 360 may be exerted on the movable core 320. Of course,gravity due to an empty weight of the movable core 320 may also beapplied to the movable core 320. Accordingly, the movable core 320 canbe moved away from the fixed core 310 to be returned to the originalposition.

The return spring 360 may be formed in any shape which is deformed tostore the restoring force and returned to its original state to transferthe restoring force to outside. In one implementation, the return spring360 may be configured as a coil spring.

The shaft 440 may be coupled through the return spring 360. The shaft440 may move up and down regardless of the deformation of the returnspring 360 in the coupled state with the return spring 360.

The return spring 360 may be accommodated in the hollow portion recessedin the upper side of the movable core 320. In addition, one end portionof the return spring 360 facing the fixed core 310, namely, an upper endportion in the illustrated implementation may be accommodated in ahollow portion recessed into a lower side of the fixed core 310.

The cylinder 370 may accommodate the fixed core 310, the movable core320, the return spring 360, and the shaft 440. The movable core 320 andthe shaft 440 may move up and down in the cylinder 370.

The cylinder 370 may be located in the hollow portion formed through thepole portion of the bobbin 340. An upper end portion of the cylinder 370may come in contact with a lower surface of the supporting plate 140.

A side surface of the cylinder 370 may come in contact with an innercircumferential surface of the pole portion of the bobbin 340. An upperopening of the cylinder 370 may be closed by the fixed core 310. A lowersurface of the cylinder 370 may come in contact with an inner surface ofthe lower frame 120.

(4) Description of Movable Contactor Part 400

The movable contactor part 400 may include the movable contactor 430 andcomponents for moving the movable contactor 430. The movable contactorpart 400 may allow the DC relay 10 to be electrically connected to anexternal power supply and a load.

The movable contactor part 400 may be accommodated in the inner space ofthe upper frame 110. The movable contactor part 400 may be accommodatedin the arc chamber 210 to be movable up and down.

The fixed contactor 220 may be located above the movable contactor part400. The movable contactor part 400 may be accommodated in the arcchamber 210 to be movable in a direction toward the fixed contactor 220and a direction away from the fixed contactor 220.

The core part 300 may be located below the movable contactor part 400.The movement of the movable contactor part 400 may be achieved by themovement of the movable core 320.

The movable contactor part 400 may include a housing 410, a cover 420, amovable contactor 430, a shaft 440, and an elastic portion 450.

The housing 410 may accommodate the movable contactor 430 and theelastic portion 450 elastically supporting the movable contactor 430.

In the illustrated implementation, the housing 410 may be formed suchthat one side and another side opposite to the one side are open (seeFIG. 5). The movable contactor 430 may be inserted through the openings.

The unopened side of the housing 410 may surround the accommodatedmovable contactor 430.

The cover 420 may be provided on a top of the housing 410. The cover 420may cover an upper surface of the movable contactor 430 accommodated inthe housing 410.

The housing 410 and the cover 420 may preferably be formed of aninsulating material to prevent unexpected electrical connection. In oneimplementation, the housing 410 and the cover 420 may be formed of asynthetic resin or the like.

A lower side of the housing 410 may be connected to the shaft 440. Whenthe movable core 320 connected to the shaft 440 is moved upward ordownward, the housing 410 and the movable contactor 430 accommodated inthe housing 410 may also be moved upward or downward.

The housing 410 and the cover 420 may be coupled by arbitrary members.In one implementation, the housing 410 and the cover 420 may be coupledby coupling members (not illustrated) such as a bolt and a nut.

The movable contactor 430 may come in contact with the fixed contactor220 when control power is applied, so that the DC relay 10 can beelectrically connected to an external power supply and a load. Whencontrol power is not applied, the movable contactor 430 may be separatedfrom the fixed contactor 220 such that the DC relay 10 can beelectrically disconnected from the external power supply and the load.

The movable contactor 430 may be located adjacent to the fixed contactor220.

An upper side of the movable contactor 430 may be covered by the cover420. In one implementation, a portion of the upper surface of themovable contactor 430 may be in contact with a lower surface of thecover 420.

A lower side of the movable contactor 430 may be elastically supportedby the elastic portion 450. In order to prevent the movable contactor430 from being arbitrarily moved downward, the elastic portion 450 mayelastically support the movable contactor 430 in a compressed state by apredetermined distance.

The movable contactor 430 may extend in the longitudinal direction,namely, in left and right directions in the illustrated implementation.That is, a length of the movable contactor 430 may be longer than itswidth. Accordingly, both end portions of the movable contactor 430 inthe longitudinal direction, accommodated in the housing 410, may beexposed to the outside of the housing 410.

Contact protrusions may protrude upward from the both end portions bypredetermined distances. The fixed contactor 220 may be brought intocontact with the contact protrusions.

The contact protrusions may be formed at positions corresponding to thefixed contactors 220 a and 220 b, respectively. Accordingly, the movingdistance of the movable contactor 430 can be reduced and contactreliability between the fixed contactor 220 and the movable contactor430 can be improved.

The width of the movable contactor 430 may be the same as a spaceddistance between the side surfaces of the housing 410. That is, when themovable contactor 430 is accommodated in the housing 410, both sidesurfaces of the movable contactor 430 in a widthwise direction may bebrought into contact with inner sides of the side surfaces of thehousing 410.

Accordingly, the state where the movable contactor 430 is accommodatedin the housing 410 can be stably maintained.

The shaft 440 may transmit driving force, which is generated in responseto the operation of the core part 300, to the movable contactor part400. Specifically, the shaft 440 may be connected to the movable core320 and the movable contactor 430. When the movable is moved upward ordownward, the movable contactor 430 may also be moved upward or downwardby the shaft 440.

The shaft 440 may extend in the longitudinal direction, namely, in theup and down (vertical) direction in the illustrated implementation.

The lower end portion of the shaft 440 may be inserted into the movablecore 320. When the movable core 320 is moved up and down, the shaft 440may also be moved up and down together with the movable core 320.

A body portion of the shaft 440 may be coupled through the fixed core310 to be movable up and down. The return spring 360 may be coupledthrough the body portion of the shaft 440.

Specifically, an upper end portion of the shaft 440 may be coupled tothe housing 410. When the movable core 320 is moved, the shaft 440 andthe housing 410 may also be moved.

The upper and lower end portions of the shaft 440 may have a largerdiameter than the body portion of the shaft. Accordingly, the coupledstate of the shaft 440 to the housing 410 and the movable core 320 canbe stably maintained.

The elastic portion 450 may elastically support the movable contactor430. When the movable contactor 430 is brought into contact with thefixed contactor 220, the movable contactor 430 may tend to be separatedfrom the fixed contactor 220 due to electromagnetic repulsive force.

At this time, the elastic portion 450 can elastically support themovable contactor 430 to prevent the movable contactor 430 from beingarbitrarily separated from the fixed contactor 220.

The elastic portion 450 may be arbitrarily configured to be capable ofstoring restoring force by being deformed and applying the storedrestoring force to another member. In one implementation, the elasticportion 450 may be configured as a coil spring.

One end portion of the elastic portion 450 facing the movable contactor430 may come in contact with the lower side of the movable contactor430. In addition, another end portion opposite to the one end portionmay come in contact with the upper side of the housing 410.

The elastic portion 450 may elastically support the movable contactor430 in a state of storing the restoring force by being compressed by apredetermined length. Accordingly, even if electromagnetic repulsiveforce is generated between the movable contactor 430 and the fixedcontactor 220, the movable contactor 430 cannot be arbitrarily moved.

A protrusion (not illustrated) inserted into the elastic portion 450 mayprotrude from the lower side of the movable contactor 430 to enablestable coupling of the elastic portion 450. Similarly, a protrusion (notillustrated) inserted into the elastic portion 450 may also protrudefrom the upper side of the housing 410.

3. Description of Arc Path Forming Unit 500 According to OneImplementation

Referring to FIG. 3, the DC relay 10 may include an arc path formingunit 500. The arc path forming unit 500 may form a path through which anarc generated inside the arc chamber 210 is moved or extinguished duringmovement.

The arc path forming unit 500 may include a main magnet (or main magnetunit) 520 and a sub magnet (or sub magnet unit) 540. The main magnet 520and the sub magnet 540 may generate magnetic fields therebetween or bythemselves.

In a state in which the magnetic fields are generated, when the fixedcontactor 220 and the movable contactor 430 are in contact with eachother, electromagnetic force may be generated accordingly. A directionof the electromagnetic force may be determined by the Fleming'sleft-hand rule.

The arc path forming unit 500 may control the direction of theelectromagnetic force by using polarities and an arrangement method ofthe main magnet 520 and the sub magnet 540.

Accordingly, a generated arc may not move toward a central portion C ofa space portion 516 of a magnet frame 510. This can prevent damage oncomponents of the DC relay 10 disposed at the central portion C.

The arc path forming unit 500 may be located in the inner space of theupper frame 110. Also, the arc path forming unit 500 may surround thearc chamber 210 at the outside of the arc chamber 210.

Hereinafter, the arc path forming unit 500 according to oneimplementation will be described in detail, with reference to FIGS. 4 to9.

The arc path forming unit 500 according to the illustratedimplementation may include a magnet frame 510, a main magnet 520, amagnetization member 530, and a sub magnet 540.

(1) Description of Magnet Frame 510

The magnet frame 510 may define an outside of the arc path forming unit500. The magnet frame 510 may surround the arc chamber 210. That is, themagnet frame 510 may be located outside the arc chamber 210.

In the illustrated implementation, the magnet frame 510 may have arectangular cross-section. That is, the magnet frame 510 may be formedsuch that a length in the lengthwise (longitudinal) direction, forexample, in the left and right direction in the illustratedimplementation is longer than a length in a widthwise direction, forexample, in the front and rear direction in the illustratedimplementation.

The shape of the magnet frame 510 may vary depending on shapes of theupper frame 110 and the arc chamber 210.

A space portion 516 defined in the magnet frame 510 may communicate withthe arc chamber 210. To this end, as described above, a through hole(not illustrated) may be formed through a wall portion of the arcchamber 210.

The magnet frame 510 may be formed of an insulating material throughwhich electricity or magnetic force does not pass. This can prevent anoccurrence of magnetic interference among the main magnet 520, themagnetization member 530, and the sub magnet 540. In one implementation,the magnet frame 510 may be formed of a synthetic resin or ceramic.

Referring to FIG. 6, the magnet frame 510 may include a first surface511, a second surface 512, a third surface 513, a fourth surface 514, anarc discharge opening 515, and a space portion 516.

The first surface 511, the second surface 512, the third surface 513,and the fourth surface 514 may define an outer circumferential surfaceof the magnet frame 510. That is, the first surface 511, the secondsurface 512, the third surface 513, and the fourth surface 514 may serveas walls of the magnet frame 510.

Outer sides of the first surface 511, the second surface 512, the thirdsurface 513, and the fourth surface 514 may be in contact with orfixedly coupled to an inner surface of the upper frame 110. In addition,the main magnet 520, the magnetization member 530, and the sub magnet540 may be disposed at inner sides of the first surface 511, the secondsurface 512, the third surface 513, and the fourth surface 514.

In the illustrated implementation, the first surface 511 may define arear surface. The second surface 512 may define a front surface and facethe first surface 511.

Also, the third surface 513 may define a left surface. The fourthsurface 514 may define a right surface and face the third surface 513.

The first surface 511 may continuously be formed with the third surface513 and the fourth surface 514. The first surface 511 may be coupled tothe third surface 513 and the fourth surface 514 at predeterminedangles. In one implementation, the predetermined angle may be a rightangle.

The second surface 512 may continuously be formed with the third surface513 and the fourth surface 514. The second surface 512 may be coupled tothe third surface 513 and the fourth surface 514 at predeterminedangles. In one implementation, the predetermined angle may be a rightangle.

Each corner at which the first surface 511 to the fourth surface 514 areconnected to one another may be chamfered.

A first main magnet 521 and a third main magnet 523 may be coupled tothe inner side of the first surface 511, namely, one side of the firstsurface 511 facing the second surface 512. In addition, a second mainmagnet 522 and a fourth main magnet 524 may be coupled to the inner sideof the second surface 512, namely, one side of the second surface 512facing the first surface 511.

A first magnetization member 531 may be coupled to the one side of thefirst surface 511. In addition, a second magnetization member 532 may becoupled to the one side of the second surface 512.

A first sub magnet 541 may be coupled to the inner side of the thirdsurface 513, namely, one side of the third surface 513 facing the fourthsurface 514. Also, a second sub magnet 542 may be coupled to the innerside of the fourth surface 514, namely, one side of the fourth surface514 facing the third surface 513.

Coupling members (not illustrated) may be provided for coupling therespective surfaces 511, 512, 513, and 514 with the main magnet 520, themagnetization member 530, and the sub magnet 540.

An arc discharge opening 515 may be formed through at least one of thefirst surface 511 and the second surface 512.

The arc discharge opening 515 may be a passage through which an arcextinguished and discharged from the arc chamber flows into the innerspace of the upper frame 110. The arc discharge opening 515 may allowthe space portion 516 of the magnet frame 510 to communicate with thespace of the upper frame 110.

In the illustrated implementation, the arc discharge opening 515 may beformed through each of the first surface 511 and the second surface 512.

The arc discharge opening 515 formed through the first surface 511 maycommunicate with a space defined by a predetermined spaced distancebetween the first main magnet 521 and the third main magnet 523. Thatis, the arc discharge opening 515 formed through the first surface 511may be defined between the first main magnet 521 and the third mainmagnet 523.

The arc discharge opening 515 formed through the second surface 512 maycommunicate with a space defined by a predetermined spaced distancebetween the second main magnet 522 and the fourth main magnet 524. Thatis, the arc discharge opening 515 formed through the second surface 512may be defined between the second main magnet 522 and the fourth mainmagnet 524.

A space surrounded by the first surface 511 to the fourth surface 514may be defined as the space portion 516.

The fixed contactor 220 and the movable contactor 430 may beaccommodated in the space portion 516. In addition, as illustrated inFIG. 4, the arc chamber 210 may be accommodated in the space portion516.

In the space portion 516, the movable contactor 430 may move toward thefixed contactor 220 or away from the fixed contactor 220.

In addition, a path A.P of an arc generated in the arc chamber 210 maybe formed in the space portion 516. This can be achieved by magneticfields generated by the main magnet 520, the magnetization member 530,and the sub magnet 540.

A central portion of the space portion 516 may be defined as a centralportion C. A same straight line distance may be set from each cornerwhere the first to fourth surfaces 511, 512, 513, and 514 are connectedto the central portion C.

The central portion C may be located between the first fixed contactor220 a and the second fixed contactor 220 b. In addition, a center of themovable contactor part 400 may be located perpendicularly below thecentral portion C. That is, centers of the housing 410, the cover 420,the movable contactor 430, the shaft 440, and the elastic portion 450may be located perpendicularly below the central portion C.

Accordingly, when a generated arc is moved toward the central portion C,those components may be damaged. To prevent such damage, the arc pathforming unit 500 may include the main magnet 520, the magnetizationmember 530, and the sub magnet 540.

(2) Description of Main Magnet 520

The main magnet 520 may generate a magnetic field inside the spaceportion 516. The magnetic field may be generated between the neighboringmain magnets 521 or by each main magnet 520.

The main magnet 520 may be configured to have magnetism by itself or toobtain magnetism by an application of current or the like. In oneimplementation, the main magnet 520 may be implemented as a permanentmagnet or an electromagnet.

The main magnet 520 may be coupled to the magnet frame 510. Couplingmembers (not illustrated) may be provided for the coupling between themain magnet 520 and the magnet frame 510.

In the illustrated implementation, the main magnet 520 may extend in thelongitudinal direction and have a rectangular parallelepiped shapehaving a rectangular cross section. The main magnet 520 may be providedin any shape capable of producing the magnetic field.

The main magnet 520 may be provided in plurality. In the illustratedimplementation, four main magnets 520 may be provided, but the numbermay vary.

The plurality of main magnets 520 may include a first main magnet 521, asecond main magnet 522, a third main magnet 523, and a fourth mainmagnet 524.

The first main magnet 521 may produce a magnetic field together with thesecond main magnet 522 or the fourth main magnet 524. In addition, thefirst main magnet 521 may generate a magnetic field by itself.

In the illustrated implementation, the first main magnet 521 may belocated to be biased to a left side on the inner side of the firstsurface 511. The first main magnet 521 may be spaced apart from thethird main magnet 523 by a predetermined distance in the longitudinaldirection, for example, in the left and right direction in theillustrated implementation.

A space defined by the predetermined distance between the first mainmagnet 521 and the third main magnet 523 may communicate with the arcdischarge opening 515 formed through the first surface 511.

The first main magnet 521 may be disposed to face the second main magnet522. Specifically, the first main magnet 521 may be disposed to face thesecond main magnet 522 with the space portion 516 therebetween.

The first main magnet 521 may include a first facing surface 521 a and afirst opposing surface 521 b.

The first facing surface 521 a may be defined as one side surface of thefirst main magnet 521 that faces the space portion 516. In other words,the first facing surface 521 a may be defined as one side surface of thefirst main magnet 521 that faces the second main magnet 522.

The first opposing surface 521 b may be defined as another side surfaceof the first main magnet 521 that faces the first surface 511. In otherwords, the first opposing surface 521 b may be defined as one sidesurface of the first main magnet 521 opposite to the first facingsurface 521 a.

The first facing surface 521 a and the first opposing surface 521 b mayhave different polarities. That is, the first facing surface 521 a maybe magnetized to one of an N pole and an S pole, and the first opposingsurface 521 b may be magnetized to another one of the N pole and the Spole.

Accordingly, a magnetic field propagating from one of the first facingsurface 521 a and the first opposing surface 521 b to the other may beproduced by the first main magnet 521 itself.

The polarity of the first facing surface 521 a may be the same as apolarity of the second facing surface 522 a of the second main magnet522. Also, the polarity of the first facing surface 521 a may be thesame as a polarity of a fourth facing surface 524 a of the fourth mainmagnet 524.

Accordingly, the first main magnet 521, the second main magnet 522, andthe fourth main magnet 524 may produce repelling magnetic fields in thespace portion 516.

The second main magnet 522 may produce a magnetic field together withthe first main magnet 521 or the third main magnet 523. In addition, thesecond main magnet 522 may generate a magnetic field by itself.

In the illustrated implementation, the second main magnet 522 may belocated to be biased to the left side on the inner side of the secondsurface 512. The second main magnet 522 may be spaced apart from thefourth main magnet 524 by a predetermined distance in the longitudinaldirection, for example, in the left and right direction in theillustrated implementation.

A space defined by the predetermined distance between the second mainmagnet 522 and the fourth main magnet 524 may communicate with the arcdischarge opening 515 formed through the second surface 512.

The second main magnet 522 may be disposed to face the first main magnet521. Specifically, the second main magnet 522 may be disposed to facethe first main magnet 521 with the space portion 516 therebetween.

The second main magnet 522 may include a second facing surface 522 a anda second opposing surface 522 b.

The second facing surface 522 a may be defined as one side surface ofthe second main magnet 522 that faces the space portion 516. In otherwords, the second facing surface 522 a may be defined as one sidesurface of the second main magnet 522 that faces the first main magnet521.

The second opposing surface 522 b may be defined as another side surfaceof the second main magnet 522 that faces the second surface 512. Inother words, the second opposing surface 522 b may be defined as oneside surface of the second main magnet 522 opposite to the second facingsurface 522 a.

The second facing surface 522 a and the second opposing surface 522 bmay have different polarities. That is, the second facing surface 522 amay be magnetized to one of the N pole and the S pole, and the secondopposing surface 522 b may be magnetized to another one of the N poleand the S pole.

Accordingly, a magnetic field propagating from one of the second facingsurface 522 a and the second opposing surface 522 b to the other may beproduced by the second main magnet 522 itself.

The polarity of the second facing surface 522 a may be the same as thepolarity of the first facing surface 521 a of the first main magnet 521.Also, the polarity of the second facing surface 522 a may be the same asa polarity of a third facing surface 523 a of the third main magnet 523.

Accordingly, the second main magnet 522, the first main magnet 521, andthe third main magnet 523 may produce repelling magnetic fields in thespace portion 516.

The third main magnet 523 may produce a magnetic field together with thesecond main magnet 522 or the fourth main magnet 524. In addition, thethird main magnet 523 may generate a magnetic field by itself.

In the illustrated implementation, the third main magnet 523 may belocated to be biased to a right side on the inner side of the firstsurface 511. The third main magnet 523 may be spaced apart from thefirst main magnet 521 by a predetermined distance in the longitudinaldirection, for example, in the left and right direction in theillustrated implementation.

A space defined by the predetermined distance between the third mainmagnet 523 and the first main magnet 521 may communicate with the arcdischarge opening 515 formed through the first surface 511.

The third main magnet 523 may be disposed to face the fourth main magnet524. Specifically, the third main magnet 523 may be disposed to face thefourth main magnet 524 with the space portion 516 therebetween.

The third main magnet 523 may include a third facing surface 523 a and athird opposing surface 523 b.

The third facing surface 523 a may be defined as one side surface of thethird main magnet 523 that faces the space portion 516. In other words,the third facing surface 523 a may be defined as one side surface of thethird main magnet 523 that faces the fourth main magnet 524.

The third opposing surface 523 b may be defined as another side surfaceof the third main magnet 523 that faces the first surface 511. In otherwords, the third opposing surface 523 b may be defined as one sidesurface of the third main magnet 523 opposite to the third facingsurface 523 a.

The third facing surface 523 a and the third opposing surface 523 b mayhave different polarities. That is, the third facing surface 523 a maybe magnetized to one of the N pole and the S pole, and the thirdopposing surface 523 b may be magnetized to another one of the N poleand the S pole.

Accordingly, a magnetic field propagating from one of the third facingsurface 523 a and the third opposing surface 523 b to the other may beproduced by the third main magnet 523 itself.

The polarity of the third facing surface 523 a may be the same as apolarity of a fourth facing surface 524 a of the fourth main magnet 524.Also, the polarity of the third facing surface 523 a may be the same asthe polarity of the second facing surface 522 a of the second mainmagnet 522.

Accordingly, the third main magnet 523, the second main magnet 522, andthe fourth main magnet 524 may produce repelling magnetic fields in thespace portion 516.

The fourth main magnet 524 may produce a magnetic field together withthe first main magnet 521 or the third main magnet 523. In addition, thefourth main magnet 524 may generate a magnetic field by itself.

In the illustrated implementation, the fourth main magnet 524 may belocated to be biased to the right side on the inner side of the secondsurface 512. The fourth main magnet 524 may be spaced apart from thesecond main magnet 522 by a predetermined distance in the longitudinaldirection, for example, in the left and right direction in theillustrated implementation.

A space defined by the predetermined distance between the fourth mainmagnet 524 and the second main magnet 522 may communicate with the arcdischarge opening 515 formed through the second surface 512.

The fourth main magnet 524 may be disposed to face the third main magnet523. Specifically, the fourth main magnet 524 may be disposed to facethe third main magnet 523 with the space portion 516 therebetween.

The fourth main magnet 524 may include a fourth facing surface 524 a anda fourth opposing surface 524 b.

The fourth facing surface 524 a may be defined as one side surface ofthe fourth main magnet 524 that faces the space portion 516. In otherwords, the fourth facing surface 524 a may be defined as one sidesurface of the fourth main magnet 524 that faces the third main magnet523.

The fourth opposing surface 524 b may be defined as another side surfaceof the fourth main magnet 524 that faces the second surface 512. Inother words, the fourth opposing surface 524 b may be defined as oneside surface of the fourth main magnet 524 opposite to the fourth facingsurface 524 a.

The fourth facing surface 524 a and the fourth opposing surface 524 bmay have different polarities. That is, the fourth facing surface 524 amay be magnetized to one of the N pole and the S pole, and the fourthopposing surface 524 b may be magnetized to another one of the N poleand the S pole.

Accordingly, a magnetic field propagating from one of the fourth facingsurface 524 a and the fourth opposing surface 524 b to the other may beproduced by the fourth main magnet 524 itself.

The polarity of the fourth facing surface 524 a may be the same as thepolarity of the third facing surface 523 a of the third main magnet 523.Also, the polarity of the fourth facing surface 524 a may be the same asthe polarity of the first facing surface 521 a of the first main magnet521.

Accordingly, the fourth main magnet 524, the first main magnet 521, andthe third main magnet 523 may produce repelling magnetic fields in thespace portion 516.

That is, the first to fourth facing surfaces 521 a, 522 a, 523 a, and524 a at which the first to fourth main magnets 521, 522, 523, and 524face one another may have the same polarity.

Accordingly, the first to fourth main magnets 521, 522, 523, and 524 mayproduce repelling magnetic fields in the space portion 516.

Referring to FIG. 7, extension lengths of the main magnets 520 may bedifferent from one another.

In the illustrated implementation, the first main magnet 521 and thefourth main magnet 524 may have short lengths and the second main magnet522 and the third main magnet 523 may extend long in length.

The arc discharge opening 515 formed through the first surface 511 maybe biased to the left side to communicate with the space between thefirst main magnet 521 and the third main magnet 523. Similarly, the arcdischarge opening 515 formed through the second surface 512 may bebiased to the right side to communicate with the space between thesecond main magnet 522 and the fourth main magnet 524.

Although not illustrated, the first main magnet 521 and the fourth mainmagnet 524 may extend long in length and the second main magnet 522 andthe third main magnet 523 may have short lengths. It will be understoodthat the positions of the arc discharge openings 515 formed at the firstsurface 511 and the second surface 512 may be changed correspondingly.

With the configuration, the magnetic fields produced by the main magnets520 facing each other may be biased toward either the left or the right.Even in this case, the magnetic fields can be produced in the spaceportion 516 by the respective main magnets 521, 522, 523, and 524 in arepelling direction.

This can prevent a generated arc from moving toward the central portionC. Also, the degree of freedom of designing the DC relay 10 can beimproved.

(3) Description of Magnetization Member 530

Referring to FIG. 8, the arc path forming unit 500 according to theillustrated implementation may include the magnetization member 530.

The magnetization member 530 may generate a magnetic field in the samedirection as the magnetic field generated by the main magnet 520. Themagnetic field produced in the space portion 516 may be strengthened bythe magnetic field produced by the magnetization member 530.

The magnetization member 530 may be formed of a magnetic substance. Inone implementation, the magnetization member 530 may be formed of iron(Fe) or the like.

The magnetization member 530 may be in contact with or connected to themain magnet 520. The magnetism of the main magnet 520 may be transferredto the magnetization member 530. Accordingly, the magnetization member530 can have the same polarity as the contacted main magnet 520.

The magnetization member 530 may be coupled to the magnet frame 510. Tothis end, a coupling member (not illustrated) may be provided.

The magnetization member 530 may be provided in plurality. In theillustrated implementation, two magnetization members 530 may beprovided, but the number may vary.

The magnetization members 530 may include a first magnetization member531 and a second magnetization member 532.

The first magnetization member 531 may be in contact with the first mainmagnet 521 and the third main magnet 523. The first magnetization member531 may be located in the space defined between the first main magnet521 and the third main magnet 523 that are spaced apart from each otherby the predetermined distance.

The first magnetization member 531 may extend in the longitudinaldirection, namely, in the left and right directions in the illustratedimplementation. The first magnetization member 531 may have the samethickness as that of the first main magnet 521 or the third main magnet523.

The first magnetization member 531 may be located on the first surface511. A communication hole (not illustrated) communicating with the arcdischarge opening 515 may be formed at the first magnetization member531.

One end portion of the first magnetization member 531 facing the firstmain magnet 521, for example, a left end portion in the illustratedimplementation, may come in contact with one end portion of the firstmain magnet 521 facing the first magnetization member 531, for example,a right end portion in the illustrated implementation.

Another end portion of the first magnetization member 531 facing thethird main magnet 523, for example, a right end portion in theillustrated implementation, may come in contact with one end portion ofthe third main magnet 523 facing the first magnetization member 531, forexample, a left end portion in the illustrated implementation.

The first magnetization member 531 may include a first magnetizationfacing surface 531 a and a first magnetization opposing surface 531 b.

The first magnetization facing surface 531 a may be defined as one sidesurface of the first magnetization member 531 that faces the spaceportion 516. In other words, the first magnetization facing surface 531a may be defined as one side surface of the first magnetization member531 that faces the second magnetization member 532.

The first magnetization opposing surface 531 b may be defined as anotherside surface of the first magnetization member 531 that faces the firstsurface 511. In other words, the first magnetization opposing surface531 b may be defined as another side surface of the first magnetizationmember 531 opposite to the first magnetization facing surface 531 a.

When the first magnetization member 531 comes in contact with the firstmain magnet 521 and the third main magnet 523, the first magnetizationfacing surface 531 a may have the same polarity as the polarity of thefirst facing surface 521 a and the third facing surface 523 a.Similarly, the first magnetization opposing surface 531 b may have thesame polarity as the polarity of the first opposing surface 521 b andthe third opposing surface 523 b.

Accordingly, the first main magnet 521, the first magnetization member531, and the third main magnet 523 can function as a single magnet.

The second magnetization member 532 may be in contact with the secondmain magnet 522 and the fourth main magnet 524. The second magnetizationmember 532 may be located in the space defined between the second mainmagnet 522 and the fourth main magnet 524 that are spaced apart fromeach other by the predetermined distance.

The second magnetization member 532 may extend in the longitudinaldirection, namely, in the left and right directions in the illustratedimplementation. The second magnetization member 532 may have the samethickness as that of the second main magnet 522 or the fourth mainmagnet 524.

The second magnetization member 532 may be located on the second surface512. A communication hole (not illustrated) communicating with the arcdischarge opening 515 may be formed at the second magnetization member532.

One end portion of the second magnetization member 532 facing the secondmain magnet 522, for example, a left end portion in the illustratedimplementation may come in contact with one end portion of the secondmain magnet 522 facing the second magnetization member 532, for example,a right end portion in the illustrated implementation.

Another end portion of the second magnetization member 532 facing thefourth main magnet 524, for example, a right end portion in theillustrated implementation may come in contact with one end portion ofthe fourth main magnet 524 facing the second magnetization member 532,for example, a left end portion in the illustrated implementation.

The second magnetization member 532 may include a second magnetizationfacing surface 532 a and a second magnetization opposing surface 532 b.

The second magnetization facing surface 532 a may be defined as one sidesurface of the second magnetization member 532 that faces the spaceportion 516. In other words, the second magnetization facing surface 532a may be defined as one side surface of the second magnetization member532 that faces the first magnetization member 531.

The second magnetization opposing surface 532 b may be defined asanother side surface of the second magnetization member 532 that facesthe second surface 512. In other words, the second magnetizationopposing surface 532 b may be defined as another side surface of thesecond magnetization member 532 opposite to the second magnetizationfacing surface 532 a.

When the second magnetization member 532 comes in contact with thesecond main magnet 522 and the fourth main magnet 524, the secondmagnetization facing surface 532 a may have the same polarity as thepolarity of the second facing surface 522 a and the fourth facingsurface 524 a. Similarly, the second magnetization opposing surface 532b may have the same polarity as the polarity of the second opposingsurface 522 b and the fourth opposing surface 524 b.

Accordingly, the second main magnet 522, the second magnetization member532, and the fourth main magnet 524 can function as a single magnet.

This can increase strength and area of the magnetic fields produced inthe space portion 516 by virtue of the magnetization member 530.Therefore, the arc path A.P can be more effectively formed by themagnetic fields with the increased strength and area.

(4) Description of Sub Magnet 540

Referring to FIG. 9, the arc path forming unit 500 according to theillustrated implementation may include the sub magnet 540.

The sub magnet 540 may produce a magnetic field in a direction tostrengthen the magnetic field produced by the main magnet 520.

The sub magnet 540 may generate a magnetic field inside the spaceportion 516. The magnetic field may be generated between the sub magnet540 and a neighboring main magnet 520 or by each sub magnet 540.

The sub magnet 540 may be configured to have magnetism by itself or toobtain magnetism by an application of current or the like. In oneimplementation, the sub magnet 540 may be implemented as a permanentmagnet or an electromagnet.

The sub magnet 540 may be coupled to the magnet frame 510. Couplingmembers (not illustrated) may be provided for the coupling between thesub magnet 540 and the magnet frame 510.

In the illustrated implementation, the sub magnet 540 may extend in thelongitudinal direction and may be formed in a rectangular parallelepipedshape having a rectangular cross section. The sub magnet 540 may beprovided in any shape capable of producing the magnetic field.

The sub magnet 540 may be provided in plurality. In the illustratedimplementation, two sub magnets 540 may be provided but the number mayvary.

The sub magnets 540 may include a first sub magnet 541 and a second submagnet 542.

The first sub magnet 541 may produce a magnetic field in a direction tostrengthen the magnetic fields generated by the first main magnet 521and the second main magnet 522.

The first sub magnet 541 may be coupled to the inner side of the thirdsurface 513. The first sub magnet 541 may be disposed to face the secondsub magnet 542 with the space portion 516 therebetween.

The first sub magnet 541 may include a first sub facing surface 541 aand a first sub opposing surface 541 b.

The first sub facing surface 541 a may be defined as one side surface ofthe first sub magnet 541 that faces the space portion 516. In otherwords, the first sub facing surface 541 a may be defined as one sidesurface of the first sub magnet 541 that faces the second sub magnet542.

The first sub opposing surface 541 b may be defined as another sidesurface of the first sub magnet 541 facing the third surface 513. Inother words, the first sub opposing surface 541 b may be defined asanother side surface of the first sub magnet 541 opposite to the firstsub facing surface 541 a.

The first sub facing surface 541 a may have the same polarity as thesecond sub facing surface 542 a. In addition, the first sub opposingsurface 541 b may have the same polarity as the second sub opposingsurface 542 b.

The first sub facing surface 541 a may have a different polarity fromthe polarity of the first to fourth facing surfaces 521 a, 522 a, 523 a,and 524 a. That is, the first sub facing surface 541 a may have the samepolarity as the first to fourth opposing surfaces 521 b, 522 b, 523 b,and 524 b.

In addition, the first sub opposing surface 541 b may have a differentpolarity from the polarity of the first to fourth opposing surfaces 521b, 522 b, 523 b, and 524 b. That is, the first sub opposing surface 541b may have the same polarity as the first to fourth facing surfaces 521a, 522 a, 523 a, and 524 a.

With the configuration, the magnetic field produced by each of the mainmagnets 521, 522, 523, and 524 and the magnetic field produced by thefirst sub magnet 541 may attract each other.

Accordingly, the magnetic field produced by each of the main magnets521, 522, 523, and 524 can be strengthened by the magnetic fieldproduced by the first sub magnet 541.

The second sub magnet 542 may produce a magnetic field in a direction tostrengthen the magnetic fields generated by the third main magnet 523and the fourth main magnet 524.

The second sub magnet 542 may be coupled to the inner side of the fourthsurface 514. The second sub magnet 542 may be disposed to face the firstsub magnet 541 with the space portion 516 therebetween.

The second sub magnet 542 may include a second sub facing surface 542 aand a second sub opposing surface 542 b.

The second sub facing surface 542 a may be defined as one side surfaceof the second sub magnet 542 that faces the space portion 516. In otherwords, the second sub facing surface 542 a may be defined as one sidesurface of the second sub magnet 542 that faces the first sub magnet541.

The second sub opposing surface 542 b may be defined as another sidesurface of the second sub magnet 542 that faces the fourth surface 514.In other words, the second sub opposing surface 542 b may be defined asanother side surface of the second sub magnet 542 opposite to the secondsub facing surface 542 a.

The second sub facing surface 542 a may have the same polarity as thefirst sub facing surface 541 a. In addition, the second sub opposingsurface 542 b may have the same polarity as the first sub opposingsurface 541 b.

The second sub facing surface 542 a may have a different polarity fromthe polarity of the first to fourth facing surfaces 521 a, 522 a, 523 a,and 524 a. That is, the second sub facing surface 542 a may have thesame polarity as the first to fourth opposing surfaces 521 b, 522 b, 523b, and 524 b.

In addition, the second sub opposing surface 542 b may have a differentpolarity from the polarity of the first to fourth opposing surfaces 521b, 522 b, 523 b, and 524 b. That is, the second sub opposing surface 542b may have the same polarity as the first to fourth facing surfaces 521a, 522 a, 523 a, and 524 a.

With the configuration, the magnetic field produced by each of the mainmagnets 521, 522, 523, and 524 and the magnetic field produced by thesecond sub magnet 542 may attract each other.

Accordingly, the magnetic field produced by each of the main magnets521, 522, 523, and 524 can be strengthened by the magnetic fieldproduced by the second sub magnet 542.

This can increase strength and area of the magnetic fields produced inthe space portion 516, compared to the case employing only the mainmagnet 520. Therefore, the arc path A.P can be more effectively formedby the magnetic fields with the increased strength and area.

The magnetization member 530 and the sub magnet 540 may be selectivelyprovided.

That is, the arc path forming unit 500 may include only the main magnet520, may include the main magnet 520 and the magnetization member 530,or may include the main magnet 520 and the sub magnet 540.

Furthermore, the arc path forming unit 500 may include all of the mainmagnet 520, the magnetization member 530, and the sub magnet 540.

4. Description of Arc Path Forming Unit 600 According to AnotherImplementation

Referring to FIG. 3, the DC relay 10 may include an arc path formingunit 600. The arc path forming unit 600 may form a path through which anarc generated inside the arc chamber 210 is moved or extinguished duringmovement.

The arc path forming unit 600 may include a main magnet 620 and a submagnet 640. The main magnet 620 and the sub magnet 640 may generatemagnetic fields therebetween or by themselves.

In a state in which the magnetic fields are generated, when the fixedcontactor 220 and the movable contactor 430 are in contact with eachother, electromagnetic force may be generated accordingly. A directionof the electromagnetic force may be determined according to theFleming's left-hand rule.

The arc path forming unit 600 may control the direction of theelectromagnetic force by using polarities and an arrangement method ofthe main magnet 620 and the sub magnet 640.

Accordingly, a generated arc may not move toward the central portion Cof the space portion 516 of the magnet frame 510. This can preventdamage on components of the DC relay 10 disposed in the central portionC.

The arc path forming unit 600 may be located in the inner space of theupper frame 110. Also, the arc path forming unit 600 may surround thearc chamber 210 at the outside of the arc chamber 210.

Hereinafter, the arc path forming unit 600 according to anotherimplementation will be described in detail, with reference to FIGS. 10to 14.

The arc path forming unit 600 according to the illustratedimplementation may include a magnet frame 610, a main magnet 620, amagnetization member 630, and a sub magnet 640.

(1) Description of Magnet Frame 610

The magnet frame 610 may define an outside of the arc path forming unit600. The magnet frame 610 may surround the arc chamber 210. That is, themagnet frame 610 may be located outside the arc chamber 210.

In the illustrated implementation, the magnet frame 610 may have arectangular cross-section. That is, the magnet frame 610 may be formedsuch that a length in the longitudinal direction, for example, in theleft and right direction in the illustrated implementation is longerthan a length in a widthwise direction, for example, in the front andrear direction in the illustrated implementation.

The shape of the magnet frame 610 may vary depending on shapes of theupper frame 110 and the arc chamber 210.

A space portion 616 defined in the magnet frame 610 may communicate withthe arc chamber 210. To this end, as described above, a through hole(not illustrated) may be formed through a wall portion of the arcchamber 210.

The magnet frame 610 may be formed of an insulating material throughwhich electricity or magnetic force does not pass. This can prevent anoccurrence of magnetic interference among the main magnet 620, themagnetization member 630, and the sub magnet 640. In one implementation,the magnet frame 610 may be formed of a synthetic resin or ceramic.

The magnet frame 610 may include a first surface 611, a second surface612, a third surface 613, a fourth surface 614, an arc discharge opening615, and a space portion 616.

The first surface 611, the second surface 612, the third surface 613,and the fourth surface 614 may define an outer circumferential surfaceof the magnet frame 610. That is, the first surface 611, the secondsurface 612, the third surface 613, and the fourth surface 614 may serveas walls of the magnet frame 610.

Outer sides of the first surface 611, the second surface 612, the thirdsurface 613, and the fourth surface 614 may be in contact with orfixedly coupled to an inner surface of the upper frame 110. In addition,the main magnet 620, the magnetization member 630, and the sub magnet640 may be disposed at inner sides of the first surface 611, the secondsurface 612, the third surface 613, and the fourth surface 614.

In the illustrated implementation, the first surface 611 may define arear surface. The second surface 612 may define a front surface and facethe first surface 611.

Also, the third surface 613 may define a left surface. The fourthsurface 614 may define a right surface and face the third surface 613.

The first surface 611 may continuously be formed with the third surface613 and the fourth surface 614. The first surface 611 may be coupled tothe third surface 613 and the fourth surface 614 at predeterminedangles. In one implementation, the predetermined angle may be a rightangle.

The second surface 612 may continuously be formed with the third surface613 and the fourth surface 614. The second surface 612 may be coupled tothe third surface 613 and the fourth surface 614 at predeterminedangles. In one implementation, the predetermined angle may be a rightangle.

Each corner at which the first surface 611 to the fourth surface 614 areconnected to one another may be chamfered.

A first main magnet 621 may be coupled to the inner side of the thirdsurface 613, namely, one side of the third surface 613 facing the fourthsurface 614. Also, a second main magnet 622 may be coupled to the innerside of the fourth surface 614, namely, one side of the fourth surface614 facing the third surface 613.

A first magnetization member 631 may be coupled to the one side of thethird surface 613. In addition, a second magnetization member 632 may becoupled to the one side of the fourth surface 614.

A first sub magnet 641 may be coupled to the inner side of the firstsurface 611, namely, one side of the first surface 611 facing the secondsurface 612. Also, a second sub magnet 642 may be coupled to the innerside of the second surface 612, namely, one side of the second surface612 facing the first surface 611.

Coupling members (not illustrated) may be provided for coupling therespective surfaces 611, 612, 613, and 614 with the main magnet 620, themagnetization member 630, and the sub magnet 640.

An arc discharge opening 615 may be formed through at least one of thethird surface 613 and the fourth surface 614.

The arc discharge opening 615 may be a passage through which an arcextinguished and discharged from the arc chamber 210 is introduced intothe inner space of the upper frame 110. The arc discharge opening 615may allow the space portion 616 of the magnet frame 610 to communicatewith the space of the upper frame 110.

In the illustrated implementation, the arc discharge opening 615 may beformed through each of the third surface 613 and the fourth surface 614.

The arc discharge opening 615 formed through the third surface 613 maycommunicate with a through hole (not illustrated) formed through thefirst main magnet 621.

Also, the arc discharge opening 615 formed through the fourth surface614 may communicate with a through hole (not illustrated) formed throughthe second main magnet 622.

A space surrounded by the first surface 611 to the fourth surface 614may be defined as the space portion 616.

The fixed contactor 220 and the movable contactor 430 may beaccommodated in the space portion 616. Although not illustrated in FIGS.10 to 14, the arc chamber 210 may be accommodated in the space portion616.

In the space portion 616, the movable contactor 430 may move toward thefixed contactor 220 or away from the fixed contactor 220.

In addition, a path A.P of an arc generated in the arc chamber 210 maybe formed in the space portion 616. This can be achieved by the magneticfields generated by the main magnet 620, the magnetization member 630,and the sub magnet 640.

A central portion of the space portion 616 may be defined as a centralportion C. A same straight line distance may be set from each cornerwhere the first to fourth surfaces 611, 612, 613, and 614 are connectedto the central portion C.

The central portion C may be located between the first fixed contactor220 a and the second fixed contactor 220 b. In addition, a center of themovable contactor part 400 may be located perpendicularly below thecentral portion C. That is, centers of the housing 410, the cover 420,the movable contactor 430, the shaft 440, and the elastic portion 450may be located perpendicularly below the central portion C.

Accordingly, when a generated arc is moved toward the central portion C,those components may be damaged. To prevent such damage, the arc pathforming unit 600 may include the main magnet 620, the magnetizationmember 630, and the sub magnet 640.

(2) Description of Main Magnet 620

The main magnet 620 may generate a magnetic field inside the spaceportion 616. The magnetic field may be generated between neighboringmain magnets 620 or by each main magnet 620.

The main magnet 620 may be configured to have magnetism by itself or toobtain magnetism by an application of current or the like. In oneimplementation, the main magnet 620 may be implemented as a permanentmagnet or an electromagnet.

The main magnet 620 may be coupled to the magnet frame 610. Couplingmembers (not illustrated) may be provided for the coupling between themain magnet 620 and the magnet frame 610.

In the illustrated implementation, the main magnet 620 may extend in thelongitudinal direction and may be formed in a rectangular parallelepipedshape having a rectangular cross section. The main magnet 620 may beprovided in any shape capable of producing the magnetic field.

The main magnet 620 may be provided in plurality. In the illustratedimplementation, two main magnets 620 may be provided but the number mayvary.

The main magnets 620 may include a first main magnet 621 and a secondmain magnet 622.

The first main magnet 621 may produce a magnetic field together with thesecond main magnet 622. In addition, the first main magnet 621 maygenerate a magnetic field by itself.

In the illustrated implementation, the first main magnet 621 may belocated on the inner side of the third surface 613. The first mainmagnet 621 may extend to have the same length as the third surface 613.

The first main magnet 621 may be disposed to face the second main magnet622. Specifically, the first main magnet 621 may be disposed to face thesecond main magnet 622 with the space portion 616 therebetween.

A through hole (not illustrate) may be formed through the first mainmagnet 621. The through hole (not illustrated) may be formed in adirection perpendicular to the longitudinal direction, for example, inthe left and right direction in the illustrated implementation.

The through hole (not illustrated) may communicate with the arcdischarge opening 615. The arc extinguished in the space portion 616 maybe discharged to the outside of the magnet frame 610 through the throughhole (not illustrated) and the arc discharge opening 615.

The first main magnet 621 may include a first facing surface 621 a and afirst opposing surface 621 b.

The first facing surface 621 a may be defined as one side surface of thefirst main magnet 621 that faces the space portion 616. In other words,the first facing surface 621 a may be defined as one side surface of thefirst main magnet 621 that faces the second main magnet 622.

The first opposing surface 621 b may be defined as another side surfaceof the first main magnet 621 that faces the third surface 613. In otherwords, the first opposing surface 621 b may be defined as one sidesurface of the first main magnet 621 opposite to the first facingsurface 621 a.

The first facing surface 621 a and the first opposing surface 621 b mayhave different polarities. That is, the first facing surface 621 a maybe magnetized to one of the N pole and the S pole, and the firstopposing surface 621 b may be magnetized to another one of the N poleand the S pole.

Accordingly, a magnetic field propagating from one of the first facingsurface 621 a and the first opposing surface 621 b to the other may beproduced by the first main magnet 621 itself.

The polarity of the first facing surface 621 a may be the same as apolarity of the second facing surface 622 a of the second main magnet622.

Accordingly, the magnetic fields that repel each other may be producedin the space portion 616 between the first main magnet 621 and thesecond main magnet 622.

The second main magnet 622 may produce a magnetic field together withthe first main magnet 621. In addition, the second main magnet 622 maygenerate a magnetic field by itself.

In the illustrated implementation, the second main magnet 622 may belocated on the inner side of the fourth surface 614. The second mainmagnet 622 may extend to have the same length as the fourth surface 614.

The second main magnet 622 may be disposed to face the first main magnet621. Specifically, the second main magnet 622 may be disposed to facethe first main magnet 621 with the space portion 616 therebetween.

The second main magnet 622 may include a second facing surface 622 a anda second opposing surface 622 b.

The second facing surface 622 a may be defined as one side surface ofthe second main magnet 622 that faces the space portion 616. In otherwords, the second facing surface 622 a may be defined as one sidesurface of the second main magnet 622 that faces the first main magnet621.

The second opposing surface 622 b may be defined as another side surfaceof the second main magnet 622 that faces the fourth surface 614. Inother words, the second opposing surface 622 b may be defined as oneside surface of the second main magnet 622 opposite to the second facingsurface 622 a.

The second facing surface 622 a and the second opposing surface 622 bmay have different polarities. That is, the second facing surface 622 amay be magnetized to one of the N pole and the S pole, and the secondopposing surface 622 b may be magnetized to another one of the N poleand the S pole.

Accordingly, a magnetic field propagating from one of the second facingsurface 622 a and the second opposing surface 622 b to the other may beproduced by the second main magnet 622 itself.

The polarity of the second facing surface 622 a may be the same as thepolarity of the first facing surface 621 a of the first main magnet 621.

Accordingly, the magnetic fields that repel each other may be producedin the space portion 616 between the second main magnet 622 and thefirst main magnet 621.

Referring to FIG. 12, the first main magnet 621 and the second mainmagnet 622 may be provided in plurality, respectively. In theillustrated implementation, each of the first main magnet 621 and thesecond main magnet 622 may be provided by two.

The plurality of first main magnets 621 may have different lengths. Inthe illustrated implementation, any one (at the rear side) of theplurality of first main magnets 621 may be longer than the other firstmain magnet 621 (at the front side).

Similarly, the plurality of second main magnets 622 may have differentlengths. In the illustrated implementation, any one (at the front side)of the plurality of second main magnets 622 may be longer than the othersecond main magnet 622 (at the rear side).

Although not illustrated, the first main magnet 621 having the longerlength may be located at the front side and the first main magnet 621having the shorter length may be located at the rear side. Similarly,the second main magnet 622 having the longer length may be located atthe rear side and the second main magnet 622 having the shorter lengthmay be located at the front side.

The plurality of first main magnets 621 may be disposed to be spacedapart from each other by a predetermined distance. The arc dischargeopening 615 formed through the third surface 613 may be located tocommunicate with the space defined by the spacing.

The plurality of second main magnets 622 may be disposed to be spacedapart from each other by a predetermined distance. The arc dischargeopening 615 formed through the fourth surface 614 may be located tocommunicate with the space defined by the spacing.

With the configuration, the magnetic fields produced by the main magnets620 facing each other may be biased toward either the left or the right.Even in this case, the magnetic fields produced in the space portion 616by the respective main magnets 621 and 622 may repel each other.

This can prevent a generated arc from moving toward the central portionC. Also, the degree of freedom of designing the DC relay 10 can beimproved.

(3) Description of Magnetization Member 630

Referring to FIG. 13, the arc path forming unit 600 according to theillustrated implementation may include the magnetization member 630.

The magnetization member 630 may generate a magnetic field in the samedirection as the magnetic field generated by the main magnet 620. Themagnetic field produced in the space portion 616 may be strengthened bythe magnetic field produced by the magnetization member 630.

The magnetization member 630 may be formed of a magnetic substance. Inone implementation, the magnetization member 630 may be formed of iron(Fe) or the like.

The magnetization member 630 may be in contact with or connected to themain magnet 620. The magnetism of the main magnet 620 may be transferredto the magnetization member 630. Accordingly, the magnetization member630 can have the same polarity as the contacted main magnet 620.

The magnetization member 630 may be coupled to the magnet frame 610. Tothis end, a coupling member (not illustrated) may be provided.

The magnetization member 630 may be provided in plurality. In theillustrated implementation, two magnetization members 630 may beprovided but the number may vary.

In the implementation illustrated in FIG. 13, the magnetization member630 may be located between the main magnets 620. That is, it will beunderstood as a modified example of the implementation in which each ofthe first main magnet 621 and the second main magnet 622 is provided inplurality as illustrated in FIG. 12.

The magnetization members 630 may include a first magnetization member631 and a second magnetization member 632.

The first magnetization member 631 may be in contact with the pluralityof first main magnets 621. The first magnetization member 631 may belocated in the space which is defined by the plurality of first mainmagnets 621 spaced apart from each other by a predetermined distance.

The first magnetization member 631 may extend in the longitudinaldirection, namely, in the front and rear directions in the illustratedimplementation. The first magnetization member 631 may have the samethickness as that of the first main magnet 521.

Both end portions of the first magnetization member 631 in thelongitudinal direction may come in contact with end portions of theplurality of first main magnets 621, respectively.

In the illustrated implementation, one end portion of the firstmagnetization member 631 facing the rear side may come in contact withthe front end portion of the first main magnet 621 located at the rearside. Also, one end portion of the first magnetization member 631 facingthe front side may come in contact with the rear end portion of thefirst main magnet 621 located at the front side.

A communication hole (not illustrated) may be formed at the firstmagnetization member 631. The arc discharge opening 615 formed throughthe third surface 613 may communicate with the communication hole (notillustrated).

The first magnetization member 631 may include a first magnetizationfacing surface 631 a and a first magnetization opposing surface 631 b.

The first magnetization facing surface 631 a may be defined as one sidesurface of the first magnetization member 631 that faces the spaceportion 616. In other words, the first magnetization facing surface 631a may be defined as one side surface of the first magnetization member631 that faces the second magnetization member 632.

The first magnetization opposing surface 631 b may be defined as anotherside surface of the first magnetization member 631 that faces the thirdsurface 613. In other words, the first magnetization opposing surface631 b may be defined as another side surface of the first magnetizationmember 631 opposite to the first magnetization facing surface 631 a.

When the first magnetization member 631 comes in contact with the firstmain magnet 521, the first magnetization facing surface 631 a may havethe same polarity as the polarity of the first facing surface 621 a.Similarly, the first magnetization opposing surface 631 b may have thesame polarity as the polarity of the first opposing surface 621 b.

Accordingly, the plurality of first main magnets 621 and the firstmagnetization member 631 may function as a single magnet.

The second magnetization member 632 may be in contact with the pluralityof second main magnets 521. The second magnetization member 632 may belocated in the space which is defined by the plurality of second mainmagnets 622 spaced apart from each other by a predetermined distance.

The second magnetization member 632 may extend in the longitudinaldirection, namely, in the front and rear directions in the illustratedimplementation. The second magnetization member 632 may have the samethickness as that of the second main magnet 621.

Both end portions of the second magnetization member 632 in thelongitudinal direction may come in contact with end portions of theplurality of second main magnets 622, respectively.

In the illustrated implementation, one end portion of the secondmagnetization member 632 facing the rear side may come in contact withthe front end portion of the second main magnet 622 located at the rearside. Also, one end portion of the second magnetization member 632facing the front side may come in contact with the rear end portion ofthe second main magnet 622 located at the front side.

A communication hole (not illustrated) may be formed at the secondmagnetization member 632. The arc discharge opening 615 formed throughthe fourth surface 614 may communicate with the communication hole (notillustrated).

The second magnetization member 632 may include a second magnetizationfacing surface 632 a and a second magnetization opposing surface 632 b.

The second magnetization facing surface 632 a may be defined as one sidesurface of the second magnetization member 632 that faces the spaceportion 616. In other words, the second magnetization facing surface 632a may be defined as one side surface of the second magnetization member632 that faces the first magnetization member 631.

The second magnetization opposing surface 632 b may be defined asanother side surface of the second magnetization member 632 that facesthe fourth surface 614. In other words, the second magnetizationopposing surface 632 b may be defined as another side surface of thesecond magnetization member 632 opposite to the second magnetizationfacing surface 632 a.

When the second magnetization member 632 comes in contact with thesecond main magnet 521, the second magnetization facing surface 632 amay have the same polarity as the polarity of the second facing surface622 a. Similarly, the second magnetization opposing surface 632 b mayhave the same polarity as the polarity of the second opposing surface622 b.

Accordingly, the plurality of second main magnets 622 and the secondmagnetization member 632 may function as a single magnet.

This can increase strength and area of the magnetic fields produced inthe space portion 616 by virtue of the magnetization member 630.Therefore, the arc path A.P can be more effectively formed by themagnetic fields with the increased strength and area.

(4) Description of Sub Magnet 640

Referring to FIG. 14, the arc path forming unit 600 according to theillustrated implementation may include the sub magnet 640.

The sub magnet 640 may produce a magnetic field in a direction tostrengthen the magnetic field produced by the main magnet 620.

The sub magnet 640 may generate a magnetic field inside the spaceportion 616. The magnetic field may be generated between the sub magnet640 and a neighboring main magnet 620 or between the sub magnets 640 ormay be generated by each sub magnet 640.

The sub magnet 640 may be configured to have magnetism by itself or toobtain magnetism by an application of current or the like. In oneimplementation, the sub magnet 640 may be implemented as a permanentmagnet or an electromagnet.

The sub magnet 640 may be coupled to the magnet frame 610. Couplingmembers (not illustrated) may be provided for the coupling between thesub magnet 640 and the magnet frame 610.

In the illustrated implementation, the sub magnet 640 may extend in thelongitudinal direction and may be formed in a rectangular parallelepipedshape having a rectangular cross section. The sub magnet 640 may beprovided in any shape capable of producing the magnetic field.

The sub magnet 640 may be provided in plurality. In the illustratedimplementation, two sub magnets 640 may be provided but the number mayvary.

The sub magnets 640 may include a first sub magnet 641 and a second submagnet 642.

The first sub magnet 641 may produce a magnetic field in a direction tostrengthen the magnetic fields generated by the first main magnet 621and the second main magnet 622.

The first sub magnet 641 may be coupled to the first surface 611. Thefirst sub magnet 641 may be disposed to face the second sub magnet 642with the space portion 616 therebetween.

The first sub magnet 641 may include a first sub facing surface 641 aand a first sub opposing surface 641 b.

The first sub facing surface 641 a may be defined as one side surface ofthe first sub magnet 641 that faces the space portion 616. In otherwords, the first sub facing surface 641 a may be defined as one sidesurface of the first sub magnet 641 that faces the second sub magnet642.

The first sub opposing surface 641 b may be defined as another sidesurface of the first sub magnet 641 that faces the first surface 611. Inother words, the first sub opposing surface 641 b may be defined asanother side surface of the first sub magnet 641 opposite to the firstsub facing surface 641 a.

The first sub facing surface 641 a may have the same polarity as thesecond sub facing surface 642 a. In addition, the first sub opposingsurface 641 b may have the same polarity as the second sub opposingsurface 642 b.

The first sub facing surface 641 a may have a different polarity fromthe polarity of the first and second facing surfaces 621 a and 622 a.That is, the first sub facing surface 641 a may have the same polarityas the polarity of the first and second opposing surfaces 621 b and 622b.

In addition, the first sub opposing surface 641 b may have a differentpolarity from the polarity of the first and second opposing surfaces 621b and 622 b. That is, the first sub opposing surface 641 b may have thesame polarity as the first and facing surfaces 621 a and 622 a.

With the configuration, the magnetic field produced by each of the firstmain magnet 621 and the second main magnet 622 and the magnetic fieldproduced by the first sub magnet 641 may attract each other.

Accordingly, the magnetic field produced by each of the first mainmagnet 621 and the second main magnet 622 can be strengthened by themagnetic field produced by the first sub magnet 641.

The second sub magnet 642 may produce a magnetic field in a direction tostrengthen the magnetic fields generated by the first main magnet 621and the second main magnet 622.

The second sub magnet 642 may be coupled to the second surface 612. Thesecond sub magnet 642 may be disposed to face the first sub magnet 641with the space portion 616 therebetween.

The second sub magnet 642 may include a second sub facing surface 642 aand a second sub opposing surface 642 b.

The second sub facing surface 642 a may be defined as one side surfaceof the second sub magnet 642 that faces the space portion 616. In otherwords, the second sub facing surface 642 a may be defined as one sidesurface of the second sub magnet 642 that faces the first sub magnet641.

The second sub opposing surface 642 b may be defined as another sidesurface of the second sub magnet 642 that faces the second surface 612.In other words, the second sub opposing surface 642 b may be defined asanother side surface of the second sub magnet 642 opposite to the secondsub facing surface 642 a.

The second sub facing surface 642 a may have the same polarity as thefirst sub facing surface 641 a. In addition, the second sub opposingsurface 642 b may have the same polarity as the first sub opposingsurface 641 b.

The second sub facing surface 642 a may have a different polarity fromthe polarity of the first and second facing surfaces 621 a and 622 a.That is, the second sub facing surface 642 a may have the same polarityas the polarity of the first and second opposing surfaces 621 b and 622b.

In addition, the second sub opposing surface 642 b may have a differentpolarity from the polarity of the first and second opposing surfaces 621b and 622 b. That is, the second sub opposing surface 642 b may have thesame polarity as the first and facing surfaces 621 a and 622 a.

With the configuration, the magnetic field produced by each of the firstmain magnet 621 and the second main magnet 622 and the magnetic fieldproduced by the second sub magnet 642 may attract each other.

Accordingly, the magnetic field produced by each of the first mainmagnet 621 and the second main magnet 622 can be strengthened by themagnetic field produced by the second sub magnet 642.

This can increase strength and area of the magnetic fields produced inthe space portion 616, compared to the case employing only the mainmagnet 620. Therefore, the arc path A.P can be more effectively formedby the magnetic fields with the increased strength and area.

The magnetization member 630 and the sub magnet 640 may be selectivelyprovided.

That is, the arc path forming unit 600 may include only the main magnet620, may include the main magnet 620 and the magnetization member 630,or may include the main magnet 620 and the sub magnet 640.

Furthermore, the arc path forming unit 600 may include all of the mainmagnet 620, the magnetization member 630, and the sub magnet 640.

5. Description of Arc Path A.P Formed by Arc Path Forming Unit 500According to One Implementation

The arc path forming unit 500 may be configured to produce magneticfields in the arc chamber 210. The produced magnetic fields may generateelectromagnetic force to form a path A. P of a generated arc.

That is, when the fixed contactor 220 and the movable contactor 430 arebrought into contact with each other and thus current flows in a statein which magnetic fields are generated in the arc chamber 210,electromagnetic force may be generated according to the Fleming'sleft-hand rule. An arc generated inside the arc chamber 210 may movealong a direction of the electromagnetic force.

Hereinafter, an arc path A.P generated by the arc path forming unit 500according to one implementation will be described in detail, withreference to FIGS. 15 to 18.

In the following description, it will be assumed that an arc isgenerated at a contact portion between the fixed contactor 220 and themovable contactor 430 right after the fixed contactor 220 and themovable contactor 430 are separated from each other.

In addition, in the following description, magnetic fields that areproduced between different main magnets 521, 522, 523, and 524 arereferred to as “Main Magnetic Fields (M.M.F)”, and a magnet fieldproduced by each of the main magnets 521, 522, 523, and 524, themagnetization member 530, or the sub magnet 540 is referred to as a “submagnetic field (S.M.F)”.

Referring to FIGS. 15 and 16, an implementation in which the arc pathforming unit 500 includes the main magnet 520 is illustrated.

FIG. 16 illustrates an implementation in which the main magnets 521,522, 523, and 524 have different lengths, but it will be understood thatthe processes and directions of producing magnetic fields andelectromagnetic forces are similar to those in the implementation ofFIG. 15.

With regard to a flowing direction of current in (a) of FIG. 15 and (a)of FIG. 16, the current may flow into the first fixed contactor 220 aand flow out through the second fixed contactor 220 b via the movablecontactor 430.

The first main magnet 521 to the fourth main magnet 524 may produce mainmagnetic fields M.M.F. The facing surfaces 521 a, 522 a, 523 a, and 524a of the respective main magnets 521, 522, 523, and 524 may have thesame polarity. In the illustrated implementation, the facing surfaces521 a, 522 a, 523 a, and 524 a may have an N pole.

As is well known, a magnetic field diverges from an N pole and convergesto an S pole. Accordingly, the main magnetic fields M.M.F generated bythe main magnets 521, 522, 523, and 524 may diverge from the facingsurfaces 521 a, 522 a, 523 a, and 524 a, respectively.

First, considering the rear side, the main magnetic fields M.M.Fdiverging from the first main magnet 521 and the third main magnet 523may move toward the fixed contactor 220 and the movable contactor 430.

Also, considering the front side, the main magnetic fields M.M.Fdiverging from the second main magnet 522 and the fourth main magnet 524may move toward the fixed contactor 220 and the movable contactor 430.

Accordingly, the main magnetic fields M.M.F diverging from therespective main magnets 521, 522, 523, and 524 may meet at the fixedcontactor 220, the movable contactor 430, and the central portion C.

A force to repel each other, that is, a repulsive force, may begenerated between the main magnetic fields M.M.F diverging from the mainmagnets 521, 522, 523, and 524. Accordingly, the main magnetic fieldsM.M.F that reach the fixed contactor 220, the movable contactor 430, andthe central portion C may start to proceed in different directions, forexample, in the left and right directions in the illustratedimplementation.

In addition, the main magnets 521, 522, 523, and 524 may continuouslyproduce the main magnetic fields M.M.F, respectively. Accordingly, themain magnetic fields M.M.F may flow toward the third surface 513 or thefourth surface 514 rather than toward the central portion C, which is anarrow space.

Specifically, at the first fixed contactor 220 a, the main magneticfield M.M.F may flow toward the third surface 513. Also, at the secondfixed contactor 220 b, the main magnetic field M.M.F may flow toward thefourth surface 514.

If the Fleming's left-hand rule is applied at the first fixed contactor220 a, the main magnetic field M.M.F is directed to the third surface513 and current flows from the upper side to the lower side. Therefore,electromagnetic force may be generated toward the rear side, namely,toward the first surface 511.

Also, if the Fleming's left-hand rule is applied at the second fixedcontactor 220 b, the main magnetic field M.M.F is directed to the fourthsurface 514 and current flows from the lower side to the upper side.Therefore, electromagnetic force may also be generated toward the rearside, namely, toward the first surface 511.

Accordingly, the arc path A.P formed by the electromagnetic force may beformed toward the rear side, that is, toward the first surface 511.

With regard to a flowing direction of current in (b) of FIG. 15 and (b)of FIG. 16, the current may flow into the second fixed contactor 220 band flow out through the first fixed contactor 220 a via the movablecontactor 430.

The directions of the main magnetic fields M.M.F produced by therespective main magnets 521, 522, 523, and 524 are as described above.

If the Fleming's left-hand rule is applied at the first fixed contactor220 a, the main magnetic field M.M.F is directed to the third surface513 and current flows from the lower side to the upper side. Therefore,electromagnetic force may be generated toward the front side, namely,toward the second surface 512.

Also, if the Fleming's left-hand rule is applied at the second fixedcontactor 220 b, the main magnetic field M.M.F is directed to the fourthsurface 514 and current flows from the upper side to the lower side.Therefore, electromagnetic force may also be generated toward the frontside, namely, toward the second surface 512.

Accordingly, the arc path A.P formed by the electromagnetic force may beformed toward the front side, that is, toward the second surface 512.

Therefore, a generated arc may proceed in a direction away from thecentral portion C. This can prevent each component of the DC relay 10densely distributed at the central portion C from being damaged due tothe arc.

Meanwhile, each of the main magnets 521, 522, 523, and 524 may produce asub magnetic field S.M.F by itself. The sub magnetic field S.M.F mayflow from each facing surface 521 a, 522 a, 523 a, 524 a toward theopposing surface 521 b, 522 b, 523 b, 524 b.

That is, the sub magnetic field S.M.F diverging from each of the mainmagnets 521, 522, 523, and 524 inside the space portion 516 may proceedin the same direction as the main magnetic field M.M.F. Accordingly, thesub magnetic field S.M.F can reinforce strength of the main magneticfield M.M.F.

Therefore, the electromagnetic force generated by the main magneticfield M.M.F can also be strengthened, thereby forming the arc path A.Pmore effectively.

Referring to FIG. 17, an implementation in which the arc path formingunit 500 includes the main magnet 520 and the magnetization member 530is illustrated.

With regard to a flowing direction of current in (a) of FIG. 17, thecurrent may flow into the first fixed contactor 220 a and flow outthrough the second fixed contactor 220 b via the movable contactor 430.

With regard to a flowing direction of current in (b) of FIG. 17, thecurrent may flow into the second fixed contactor 220 b and flow outthrough the first fixed contactor 220 a via the movable contactor 430.

As aforementioned, the main magnetic field M.M.F and the sub magneticfield S.M.F may be produced by each of the main magnets 521, 522, 523,and 524, and thus the electromagnetic force forming the arc path A.P maybe generated.

Therefore, hereinafter, a process in which the main magnetic field M.M.Fis strengthened by the magnetization member 530 will be mainlydescribed.

The first magnetization member 531 may be in contact with the first mainmagnet 521 and the third main magnet 523. The first magnetization facingsurface 531 a may have the same polarity as the polarity of the firstfacing surface 521 a and the third facing surface and 523 a. In theillustrated implementation, the first magnetization facing surface 531 amay have an N pole.

The second magnetization member 532 may be in contact with the secondmain magnet 522 and the fourth main magnet 524. The second magnetizationfacing surface 532 a may have the same polarity as the polarity of thesecond facing surface 522 a and the fourth facing surface and 524 a. Inthe illustrated implementation, the second magnetization facing surface532 a may have the N pole.

The magnetic fields diverging from the first magnetization facingsurface 531 a and the second magnetization facing surface 532 a may flowtoward the fixed contactor 220, the movable contactor 430, and thecentral portion C. Accordingly, the magnetic fields diverging from therespective magnetization facing surfaces 531 a and 532 a may meet at thefixed contactor 220, the movable contactor 430, and the central portionC.

At this time, since each magnetization facing surface 531 a and 532 ahave the same polarity, for example, the N pole in the illustratedimplementation, force to repel each other, i.e., repulsive force may begenerated between the magnetic fields.

Accordingly, the magnetic fields diverging from the magnetization facingsurfaces 531 a and 532 a may flow similarly to the flowing direction ofthe aforementioned main magnetic fields M.M.F.

Specifically, the magnetic fields diverging from the first magnetizationfacing surface 531 a and the second magnetization facing surface 523 amay move toward the third surface 513 or the fourth surface 514.

Accordingly, the main magnetic fields M.M.F diverging from the mainmagnets 521, 522, 523, and 524 and the magnetic fields diverging fromthe magnetization members 531 and 532 may be superimposed at the fixedcontactors 220 a and 220 b.

In addition, the magnetic fields diverging from the magnetizationmembers 531 and 532 may move along the same path as the main magneticfields M.M.F. This can increase the strength of the main magnetic fieldM.M.F.

Therefore, the electromagnetic force generated at the fixed contactors220 a and 220 b can also be strengthened, thereby forming the arc pathA.P effectively.

As described above, the electromagnetic force may move toward the rearside, that is, toward the first surface 511 in (a) of FIG. 17. Also, theelectromagnetic force may move toward the rear side, that is, toward thesecond surface 512 in (b) of FIG. 17.

Meanwhile, the magnetization members 531 and 532 may produce the submagnetic fields S.M.F. The sub magnetic fields S.M.F may move from themagnetization facing surfaces 531 a and 532 a toward the magnetizationopposing surfaces 531 b and 532 b, respectively.

That is, the sub magnetic fields S.M.F diverging from the magnetizationmembers 531 and 532 may move in the same direction as the sub magneticfields S.M.F diverging from the main magnets 521, 522, 523, and 524inside the space portion 516.

Accordingly, the sub magnetic fields S.M.F diverging from themagnetization members 531 and 532 can increase the strength of the mainmagnetic fields M.M.F and the sub magnetic fields S.M.F diverging fromthe main magnets 521, 522, 523, and 524.

In addition, as described above, the magnetization members 531 and 532may be connected to the main magnets 521, 522, 523, and 524, so as tofunction as the single magnet. Accordingly, a magnetic field may beproduced between the magnetization members 531 and 532 in the samedirection as the main magnetic fields M.M.F produced by the main magnets521, 522, 523, and 524.

Therefore, the electromagnetic force generated by the main magneticfield M.M.F can also be strengthened, thereby forming the arc path A.Pmore effectively.

Referring to FIG. 18, an implementation in which the arc path formingunit 500 includes the main magnet 520 and the sub magnet 540 isillustrated.

With regard to a flowing direction of current in (a) of FIG. 18, thecurrent may flow into the first fixed contactor 220 a and flow outthrough the second fixed contactor 220 b via the movable contactor 430.

With regard to a flowing direction of current in (b) of FIG. 18, thecurrent may flow into the second fixed contactor 220 b and flow outthrough the first fixed contactor 220 a via the movable contactor 430.

As aforementioned, the main magnetic field M.M.F and the sub magneticfield S.M.F may be produced by each of the main magnets 521, 522, 523,and 524, and thus the electromagnetic force forming the arc path A.P maybe generated.

Therefore, hereinafter, a process in which the main magnetic field M.M.Fis strengthened by the sub magnet 540 will be mainly described.

Each sub magnet 540 may be disposed on a surface of the magnet frame 510on which the main magnet 520 is not disposed. In the illustratedimplementation, the main magnets 520 may be located on the first surface511 and the second surface 512, and thus the sub magnets 540 may belocated on the third surface 513 and the fourth surface 514.

Specifically, the first sub magnet 541 may be located on the thirdsurface 513 and the second sub magnet 542 on the fourth surface 514.

The sub facing surfaces 541 a and 542 a of the sub magnets 541 and 542may have a polarity different from that of the facing surfaces 521 a,522 a, 523 a, and 524 a. In the illustrated implementation, the facingsurfaces 521 a, 522 a, 523 a, and 524 a may have the N pole, and thusthe sub facing surfaces 541 a and 542 a may have the S pole.

Accordingly, the sub magnets 541 and 542 may produce magnetic fields ina direction converging to the sub facing surfaces 541 a and 542 a.

Therefore, the main magnetic fields M.M.F diverging from the first mainmagnet 521 and the second main magnet 522 may move toward the first submagnet 541. Also, the main magnetic fields M.M.F diverging from thethird main magnet 523 and the fourth main magnet 524 may move toward thesecond sub magnet 542.

Accordingly, the main magnetic fields M.M.F may move not only in adirection diverging from each of the main magnets 521, 522, 523, and 524but also in a direction converging to each of the sub magnets 541 and542.

Accordingly, the strength of the main magnetic fields M.M.F produced atthe first fixed contactor 220 a can further be increased in thedirection toward the first sub magnet 541, that is, toward the thirdsurface 513.

Likewise, the main magnetic fields M.M.F produced at the second fixedcontactor 220 b can further be strengthened in the direction toward thesecond sub magnet 542, that is, toward the fourth surface 514.

Therefore, the electromagnetic force generated at the fixed contactors220 a and 220 b can also be strengthened by the main magnetic fieldsM.M.F, thereby forming the arc path A.P effectively.

The foregoing description has been mainly given of the implementation inwhich each of the facing surfaces 521 a, 522 a, 523 a, and 524 a has theN pole, but another implementation in which each of the facing surfaces521 a, 522 a, 523 a, and 524 a has the S pole may also be considered. Inthis case, it will be understood that a direction of electromagneticforce and an arc path A.P are formed opposite to those of the previousimplementation.

As described above, in the arc path forming unit 500, the arc may notmove toward the central portion C regardless of the direction of thecurrent applied to the fixed contactor 220. That is, the arc path A.Pformed by the arc path forming unit 500 may be formed to extend towardthe front or rear side, other than toward the central portion C.

Therefore, each component densely distributed at the central portion Ccannot be damaged by the arc.

6. Description of Arc Path A.P Formed by Arc Path Forming Unit 600According to Another Implementation

The arc path forming unit 600 may be configured to produce a magneticfield in the arc chamber 210. The produced magnetic field may generateelectromagnetic force to form a path A.P of a generated arc.

That is, when the fixed contactor 220 and the movable contactor 430 arebrought into contact with each other and thus current flows in a statein which a magnetic field is generated in the arc chamber 210,electromagnetic force may be generated according to the Fleming'sleft-hand rule. An arc generated inside the arc chamber 210 may movealong a direction of the electromagnetic force.

Hereinafter, an arc path A.P generated by the arc path forming unit 600according to one implementation will be described in detail, withreference to FIGS. 19 to 22.

In the following description, it will be assumed that an arc isgenerated at a contact portion between the fixed contactor 220 and themovable contactor 430 right after the fixed contactor 220 and themovable contactor 430 are separated from each other.

In addition, in the following description, a magnetic field that isproduced between the different main magnets 621 and 622 is referred toas a “Main Magnetic Field (M.M.F)”, and a magnet field produced by eachof the main magnets 621 and 622, the magnetization member 630, or thesub magnet 640 is referred to as a “sub magnetic field (S.M.F)”.

Referring to FIGS. 19 and 20, an implementation in which the arc pathforming unit 600 includes the main magnet 620 is illustrated.

FIG. 20 illustrates an implementation in which each of the main magnets621 and 622 is provided in plurality and the plurality of main magnets621 and the plurality of main magnets 622 have different lengths,respectively. However, it will be understood that the processes anddirections of producing magnetic fields and electromagnetic forces aresimilar to those in the implementation of FIG. 19.

With regard to a flowing direction of current in (a) of FIG. 19 and (a)of FIG. 20, the current may flow into the first fixed contactor 220 aand flow out through the second fixed contactor 220 b via the movablecontactor 430.

The first main magnet 621 and the second main magnet 622 may producemain magnetic fields M.M.F. The facing surfaces 621 a and 622 a of therespective main magnets 621 and 622 may have the same polarity. In theillustrated implementation, the facing surfaces 621 a and 622 a may havean N pole.

As is well known, a magnetic field diverges from an N pole and convergesto an S pole. Accordingly, the main magnetic fields M.M.F generated bythe main magnets 621 and 622 may diverge from the facing surfaces 621 aand 622 a, respectively.

First, considering a left side, the main magnetic field M.M.F divergingfrom the first main magnet 621 may move toward the fixed contactor 220and the movable contactor 430.

Also, considering a right side, the main magnetic field M.M.F divergingfrom the second main magnet 622 may move toward the fixed contactor 220and the movable contactor 430.

Accordingly, the main magnetic fields M.M.F diverging from therespective main magnets 621 and 622 may meet at the central portion C ofthe space portion 616. A force to repel each other, that is, a repulsiveforce, may be generated between the main magnetic fields M.M.F divergingfrom the main magnets 621 and 622.

Accordingly, the main magnetic fields M.M.F that reach the centralportion C may start to proceed in different directions, for example, inthe left and right directions in the illustrated implementation.

In addition, the main magnets 621 and 622 may continuously produce themain magnetic fields M.M.F, respectively. Accordingly, the main magneticfields M.M.F may flow toward the first surface 511 or the fourth surface514.

Therefore, at the first fixed contactor 220 a, the main magnetic fieldM.M.F may flow toward the central portion C or the fourth surface 614,namely, toward the right side in the illustrated implementation. Also,at the second fixed contactor 220 b, the main magnetic field M.M.F mayflow toward the central portion C or the third surface 613, namely,toward the left side in the illustrated implementation.

If the Fleming's left-hand rule is applied at the first fixed contactor220 a, the main magnetic field M.M.F is directed to the fourth surface614 and current flows from the upper side to the lower side. Therefore,electromagnetic force may be generated toward the front side, namely,toward the second surface 612.

Also, if the Fleming's left-hand rule is applied at the second fixedcontactor 220 b, the main magnetic field M.M.F is directed to the thirdsurface 613 and current flows from the lower side to the upper side.Therefore, electromagnetic force may also be generated toward the frontside, namely, toward the second surface 612.

Accordingly, the arc path A.P formed by the electromagnetic force may beformed toward the front side, that is, toward the second surface 612.

With regard to a flowing direction of current in (b) of FIG. 19 and (b)of FIG. 20, the current may flow into the second fixed contactor 220 band flow out through the first fixed contactor 220 a via the movablecontactor 430.

The directions of the main magnetic fields M.M.F produced by therespective main magnets 621 and 622 are as described above.

If the Fleming's left-hand rule is applied at the first fixed contactor220 a, the main magnetic field M.M.F is directed to the fourth surface614 and current flows from the lower side to the upper side. Therefore,electromagnetic force may be generated toward the rear side, namely,toward the first surface 611.

Also, if the Fleming's left-hand rule is applied at the second fixedcontactor 220 b, the main magnetic field M.M.F is directed to the thirdsurface 613 and current flows from the upper side to the lower side.Therefore, electromagnetic force may also be generated toward the rearside, namely, toward the first surface 611.

Accordingly, the arc path A.P formed by the electromagnetic force may beformed toward the rear side, that is, toward the first surface 611.

Therefore, a generated arc may proceed in a direction away from thecentral portion C. This can prevent each component of the DC relay 10densely distributed at the central portion C from being damaged due tothe arc.

Meanwhile, the main magnets 621 and 622 may produce the sub magneticfields S.M.F. The sub magnetic fields S.M.F may move from the facingsurfaces 621 a and 622 a toward the opposing surfaces 621 b and 622 b,respectively.

That is, the sub magnetic field S.M.F diverging from each of the mainmagnets 621 and 622 inside the space portion 616 may proceed in the samedirection as the main magnetic field M.M.F. Accordingly, the submagnetic field S.M.F can reinforce the strength of the main magneticfield M.M.F.

Therefore, the electromagnetic force generated by the main magneticfield M.M.F can also be strengthened, thereby forming the arc path A.Pmore effectively.

Referring to FIG. 21, an implementation in which the arc path formingunit 600 includes the main magnet 620 and the magnetization member 630is illustrated.

With regard to a flowing direction of current in (a) of FIG. 21, thecurrent may flow into the first fixed contactor 220 a and flow outthrough the second fixed contactor 220 b via the movable contactor 430.

With regard to a flowing direction of current in (b) of FIG. 21, thecurrent may flow into the second fixed contactor 220 b and flow outthrough the first fixed contactor 220 a via the movable contactor 430.

As aforementioned, the main magnetic field M.M.F and the sub magneticfield S.M.F may be produced by each of the main magnets 621 and 622, andthus the electromagnetic force forming the arc path A.P may begenerated.

Therefore, hereinafter, a process in which the main magnetic field M.M.Fis strengthened by the magnetization member 630 will be mainlydescribed.

The first magnetization member 631 may be in contact with the first mainmagnet 621. The first magnetization facing surface 631 a may have thesame polarity as the first facing surface 621 a. In the illustratedimplementation, the first magnetization facing surface 631 a may have anN pole.

The second magnetization member 632 may be in contact with the secondmain magnet 622. The second magnetization facing surface 632 a may havethe same polarity as the second facing surface 622 a. In the illustratedimplementation, the second magnetization facing surface 632 a may havethe N pole.

The magnetic fields diverging from the first magnetization facingsurface 631 a and the second magnetization facing surface 632 a may flowtoward the central portion C. Specifically, the magnetic field divergingfrom the first magnetization facing surface 631 a may proceed toward thefourth surface 614. Also, the magnetic field diverging from the secondmagnetization facing surface 632 a may proceed toward the third surface613.

Accordingly, the magnetic fields diverging from the respectivemagnetization facing surfaces 631 a and 632 a may meet at the centralportion C.

At this time, since each of the magnetization facing surfaces 631 a and632 a has the same polarity, for example, the N pole in the illustratedimplementation, force to repel each other, i.e., repulsive force may begenerated between the magnetic fields.

Accordingly, the magnetic fields diverging from the magnetization facingsurfaces 631 a and 632 a may flow similarly to the flowing direction ofthe aforementioned main magnetic fields M.M.F.

Accordingly, not only the main magnetic fields M.M.F diverging from themain magnets 621 and 622 but also the magnetic fields diverging from themagnetization members 631 and 632 can be produced at the fixedcontactors 220 a and 220 b.

In addition, the magnetic fields diverging from the magnetizationmembers 631 and 632 may move along the same path as the main magneticfields M.M.F. This can reinforce the strength of the main magnetic fieldM.M.F.

Therefore, the electromagnetic force generated at the fixed contactors220 a and 220 b can also be strengthened, thereby forming the arc pathA.P effectively.

Of course, as aforementioned, the electromagnetic force may move towardthe front side, that is, toward the second surface 612 in (a) of FIG.21. Also, the electromagnetic force may move toward the rear side, thatis, toward the first surface 611 in (b) of FIG. 21.

Meanwhile, the magnetization members 631 and 632 may produce the submagnetic fields S.M.F. The sub magnetic fields S.M.F may move from themagnetization facing surfaces 631 a and 632 a toward the magnetizationopposing surfaces 631 b and 632 b, respectively.

That is, the sub magnetic fields S.M.F diverging from the magnetizationmembers 631 and 632 may move in the same direction as the sub magneticfields S.M.F diverging from the main magnets 621 and 622 inside thespace portion 616.

Accordingly, the sub magnetic fields S.M.F diverging from themagnetization members 631 and 632 can increase the strength of the mainmagnetic fields M.M.F and the sub magnetic fields S.M.F diverging fromthe main magnets 621 and 622.

In addition, as described above, the magnetization members 631 and 632may be connected to the main magnets 621 and 622, so as to function asthe single magnet. Accordingly, a magnetic field may be produced betweenthe magnetization members 631 and 632 in the same direction as the mainmagnetic fields M.M.F produced by the main magnets 621 and 622.

Therefore, the electromagnetic force generated by the main magneticfield M.M.F can also be strengthened, thereby forming the arc path A.Pmore effectively.

Referring to FIG. 22, an implementation in which the arc path formingunit 600 includes the main magnet 620 and the sub magnet 640 isillustrated.

With regard to a flowing direction of current in (a) of FIG. 22, thecurrent may flow into the first fixed contactor 220 a and flow outthrough the second fixed contactor 220 b via the movable contactor 430.

With regard to a flowing direction of current in (b) of FIG. 22, thecurrent may flow into the second fixed contactor 220 b and flow outthrough the first fixed contactor 220 a via the movable contactor 430.

As aforementioned, the main magnetic field M.M.F and the sub magneticfield S.M.F may be produced by each of the main magnets 621 and 622, andthus the electromagnetic force forming the arc path A.P may begenerated.

Therefore, hereinafter, a process in which the main magnetic field M.M.Fis strengthened by the sub magnet 640 will be mainly described.

Each sub magnet 640 may be disposed on a surface of the magnet frame 610on which the main magnet 620 is not disposed. In the illustratedimplementation, the main magnets 620 may be located on the third surface613 and the fourth surface 614, and thus the sub magnets 640 may belocated on the first surface 611 and the second surface 612.

Specifically, the first sub magnet 641 may be located on the firstsurface 611 and the second sub magnet 642 on the second surface 612.

The sub facing surfaces 641 a and 642 a of the sub magnets 641 and 642may have a polarity different from that of the facing surfaces 621 a and622 a. In the illustrated implementation, the facing surfaces 621 a and622 a may have the N pole, and thus the sub facing surfaces 641 a and642 a may have the S pole.

Accordingly, the sub magnets 641 and 642 may produce magnetic fieldsconverging to the sub facing surfaces 641 a and 642 a.

The main magnetic fields M.M.F diverging from the first main magnet 621and the second main magnet 622 may move toward the first sub magnet 641or the second sub magnet 642.

Accordingly, the main magnetic fields M.M.F may move not only in adirection diverging from each of the main magnets 621 and 622 but alsoin a direction converging to each of the sub magnets 641 and 642.

Therefore, the main magnetic field M.M.F at the first fixed contactor220 a can be more strengthened in a direction toward the central portionC or the second main magnet 620, namely, toward the right side in theillustrated implementation.

Similarly, the strength of the main magnetic field M.M.F at the secondfixed contactor 220 b can be more strengthened in a direction toward thecentral portion C or the first main magnet 621, namely, toward the leftside in the illustrated implementation.

Therefore, the electromagnetic force generated at the fixed contactors220 a and 220 b can also be strengthened by the main magnetic fieldsM.M.F, thereby forming the arc path A.P effectively.

The foregoing description has been mainly given of the implementation inwhich each of the facing surfaces 621 a and 622 a has the N pole, butanother implementation in which each of the facing surfaces 621 a and622 a has an S pole may also be considered. In this case, it will beunderstood that a direction of electromagnetic force and an arc path A.Pare formed opposite to those of the previous implementation.

As described above, in the arc path forming unit 600, the arc may notmove toward the central portion C regardless of the direction of thecurrent applied to the fixed contactor 220. That is, the arc path A.Pformed by the arc path forming unit 600 may be formed to extend towardthe front or rear side, other than toward the central portion C.

Therefore, each component densely distributed at the central portion Ccannot be damaged by the arc.

Although it has been described above with reference to preferredimplementations of the present disclosure, it will be understood thatthose skilled in the art are able to variously modify and change thepresent disclosure without departing from the spirit and scope of theinvention described in the claims below.

-   -   10: DC relay    -   100: Frame part    -   110: Upper frame    -   120: Lower frame    -   130: Insulating plate    -   140: Supporting plate    -   200: Opening/closing part    -   210: Arc chamber    -   220: Fixed contactor    -   220 a: First fixed contactor    -   220 b: Second fixed contactor    -   230: Sealing member    -   300: Core part    -   310: Fixed core    -   320: Movable core    -   330: York    -   340: Bobbin    -   350: Coil    -   360: Return spring    -   370: Cylinder    -   400: Movable contactor part    -   410: Housing    -   420: Cover    -   430: Movable contactor    -   440: Shaft    -   450: Elastic portion    -   500: Arc path forming unit according to first implementation    -   510: Magnet frame    -   511: First surface    -   512: Second surface    -   513: Third surface    -   514: Fourth surface    -   515: Arc discharge opening    -   516: Space portion    -   520: Main magnet    -   521: First main magnet    -   521 a: First facing surface    -   521 b: First opposing surface    -   522: Second main magnet    -   522 a: Second facing surface    -   522 b: Second opposing surface    -   523: Third main magnet    -   523 a: Third facing surface    -   523 b: Third opposing surface    -   524: Fourth main magnet    -   524 a: Fourth facing surface    -   524 b: Fourth opposing surface    -   530: Magnetization member    -   531: First magnetization member    -   531 a: First magnetization facing surface    -   531 b: First magnetization opposing surface    -   532: Second magnetization member    -   532 a: Second magnetization facing surface    -   532 b: Second magnetization opposing surface    -   540: Sub magnet    -   541: First sub magnet    -   541 a: First sub facing surface    -   541 b: First sub opposing surface    -   542: Second sub magnet    -   542 a: Second sub facing surface    -   542 b: Second sub opposing surface    -   600: Arc path forming unit according to second implementation    -   610: Magnet frame    -   611: First surface    -   612: Second surface    -   613: Third surface    -   614: Fourth surface    -   615: Arc discharge opening    -   616: Space portion    -   620: Main magnet    -   621: First main magnet    -   621 a: First facing surface    -   621 b: First opposing surface    -   622: Second main magnet    -   622 a: Second facing surface    -   622 b: Second opposing surface    -   630: Magnetization member    -   631: First magnetization member    -   631 a: First magnetization facing surface    -   631 b: First magnetization opposing surface    -   632: Second magnetization member    -   632 a: Second magnetization facing surface    -   632 b: Second magnetization opposing surface    -   640: Sub magnet    -   641: First sub magnet    -   641 a: First sub facing surface    -   641 b: First sub opposing surface    -   642: Second sub magnet    -   642 a: Second sub facing surface    -   642 b: Second sub opposing surface    -   1000: DC relay according to the related art    -   1100: Fixed contact according to the related art    -   1200: Movable contact according to the related art    -   1300: Permanent magnet according to the related art    -   1310: First permanent magnet according to the related art    -   1320: Second permanent magnet according to the related art    -   C: Central portion of space portion 516, 616    -   M.M.F: Main magnetic field    -   S.M.F: Sub magnetic field    -   A.P: Arc path

1. An arc path forming unit comprising: a magnet frame having an innerspace, and comprising two pairs of surfaces facing each other andsurrounding the inner space; and main magnets accommodated in the innerspace and coupled to any one pair of surfaces extending shorter amongthe two pairs of surfaces, wherein a fixed contactor and a movablecontactor configured to be brought into contact with or separated fromthe fixed contactor are accommodated in the inner space, and wherein themain magnets coupled to the one pair of surfaces have facing surfaces,respectively, that face each other, and have a same polarity so as toform a discharge path of an arc generated when the fixed contactor andthe movable contactor are separated from each other.
 2. The arc pathforming unit of claim 1, wherein the main magnets comprise: a first mainmagnet coupled to any one of the one pair of surfaces; and a second mainmagnet coupled to another one of the one pair of surfaces and disposedto face the first main magnet.
 3. The arc path forming unit of claim 2,wherein facing surfaces of the first main magnet and the second mainmagnet that face each other have a same polarity.
 4. The arc pathforming unit of claim 3, wherein the facing surfaces of the first mainmagnet and the second main magnet that face each other have an N pole.5. The arc path forming unit of claim 3, further comprising sub magnetscoupled to another pair of surfaces extending longer among the two pairsof surfaces of the magnet frame, and wherein facing surfaces of the submagnets that face each other have a same polarity.
 6. The arc pathforming unit of claim 5, wherein the facing surfaces of the sub magnetsthat face each other have a different polarity from the polarity of thefacing surfaces of the first main magnet and the second main magnet. 7.The arc path forming unit of claim 3, wherein arc discharge openings areformed through another pair of surfaces extending shorter among the twopairs of surfaces of the magnet frame, such that the inner spacecommunicates with an outside of the magnet frame.
 8. The arc pathforming unit of claim 3, wherein the first main magnet is provided inplurality, the plurality of first main magnets spaced apart from eachother by a predetermined distance, and wherein the second main magnet isprovided in plurality, the plurality of second main magnets spaced apartfrom each other by a predetermined distance.
 9. The arc path formingunit of claim 8, wherein magnetization members are disposed between theplurality of first main magnets and between the plurality of second mainmagnets, respectively, such that the plurality of first main magnets andthe magnetization member are connected to each other and the pluralityof second main magnets and the magnetization member are connected toeach other.
 10. A Direct Current (DC) relay comprising: a fixedcontactor; a movable contactor configured to be brought into contactwith or separated from the fixed contactor; an arc path forming unithaving an inner space for accommodating the fixed contactor and themovable contactor, and configured to produce magnetic fields in theinner space so as to form a discharge path of an arc that is generatedwhen the fixed contactor and the movable contactor are separated fromeach other; and a frame part configured to accommodate the arc pathforming unit, wherein the arc path forming unit comprises: a magnetframe having an inner space, and comprising two pairs of surfaces facingeach other and surrounding the inner space; and main magnetsaccommodated in the inner space and coupled to any one pair of surfacesextending shorter among the two pairs of surfaces, wherein a fixedcontactor and a movable contactor configured to be brought into contactwith or separated from the fixed contactor are accommodated in the innerspace, and wherein the main magnets coupled to the one pair of surfaceshave facing surfaces, respectively, which face each other and have asame polarity so as to form the discharge path of the arc generated whenthe fixed contactor and the movable contactor are separated from eachother.
 11. The direct current relay of claim 10, wherein the mainmagnets comprise: a first main magnet coupled to any one of the one pairof surfaces; and a second main magnet coupled to another one of the onepair of surfaces and disposed to face the first main magnet, whereinfacing surfaces of the first main magnet and the second main magnet thatface each other have a same polarity.
 12. The direct current relay ofclaim 11, wherein the arc path forming unit comprises sub magnetscoupled to another pair of surfaces extending longer among the two pairsof surfaces of the frame part, wherein facing surfaces of the submagnets that face each other have a same polarity, and wherein thefacing surfaces of the sub magnets that face each other have a differentpolarity from the polarity of the facing surfaces of the first mainmagnet and the second main magnet.
 13. The direct current relay of claim11, wherein the first main magnet is provided in plurality, theplurality of first main magnets spaced apart from each other by apredetermined distance, and wherein the second main magnet is providedin plurality, the plurality of second main magnets spaced apart fromeach other by a predetermined distance.
 14. The direct current relay ofclaim 13, wherein one of the plurality of first main magnets is shorterthan another first main magnet, and wherein one of the plurality ofsecond main magnets is shorter than another second main magnet.
 15. Thedirect current relay of claim 13, wherein magnetization members aredisposed between the plurality of first main magnets and between theplurality of second main magnets, respectively, such that the pluralityof first main magnets and the magnetization member are connected to eachother and the plurality of second main magnets and the magnetizationmember are connected to each other.
 16. The direct current relay ofclaim 11, wherein the first main magnet and the second main magnetcomprise opposing surfaces opposite to the facing surfaces,respectively, and coming in contact with the surfaces of the magnetframe, and wherein a main magnetic field is produced between the firstmain magnet and the second main magnet, and a sub magnetic field isproduced between the facing surfaces and the opposing surfaces of thefirst main magnet and the second main magnet, such that the sub magneticfield strengthens the main magnetic field.